family finance basics: a fun guide to a serious topic

Note: This guide reflects my personal experience as a parent, not financial advice. I am not a licensed financial advisor. For major decisions - mortgages, investment strategy, tax planning, retirement - consult a professional.

what does “family finance” actually mean, and what makes it different from personal finance?

short answer: “family finance” is what happens when multiple people, one or more incomes, varied personal and budget goals, and 1 or more kids’ costs all collide in one shared budget. Family finance is not just your budget - it impacts more than just one person - and it happens to be the case that you care about all of those people, sometimes, more than yourself.

Personal finance is hard. Family finance is personal finance on steroids. Your partner may not share the same financial goals or opinions about money as you. Your children will almost certainly require a seemingly endless stream of school fees, private lessons, sports gear, healthcare appointments, and snacks (I mean, you gotta feed them).

The good news is that most of the underlying ideas are the same - spend less than you earn, save for the cloudy days, invest responsibly (don’t try to time the market), avoid high-interest debt, among other things.

The hard part is that actually implementing these ideas inside a family structure is much harder than if you were doing it for yourself. Every decision now involves at least two adults, and maybe even some of your children. In-laws? Welcome to the party. Don’t be surprised if your budget looks completely different in June than it did in January.

In this guide, I’m not going to try to teach you investment strategy or stock picking. This is a practical, family-focused layer on top of your own personal finance. It’s the stuff you mostly figure out as you go, that most people get wrong for roughly the first ten years of marriage and family.

Luckily, you’ve found this guide, so you’re already 2 steps ahead! Good luck (you’ll need it)!

why is family finance harder than personal finance?

short answer: you’re dealing with more incomes, more goals, more people who can (or need to) spend money, more lifecycle stages, and more emotional weight on every decision (this is the big one). This is one of the reasons that most “personal finance” apps don’t work well for families - they’re generally designed for one person, or if they are designed for families, other family members are treated as second class citizens in the app.

When I started tracking my finances, I had just graduated college. I was very, very single, which is probably a story for another day. Back then, things were simple: my paycheck goes into my bank account, my money pays my rent and bills, the rest is savings. One savings account, one checking account, and cash.

I would always know if I overspent, because I was the one that did it. I had one spreadsheet to track everything, but truthfully, I didn’t even need that.

Things got a bit more complicated when I got married. My spouse’s paycheck (although sporadic) added a wrinkle to our plans, but it was a good one. The tricky part is that we now had another set of expenses and a totally new set of priorities.

Navigating a budget with 2 people over the long term means making compromises, helping each other out, and coming to an agreement on how to spend money. You may re-visit some discussions more than once (and that may be the understatement of the century). If you can address the key challenges in a partner-owned budget, you will already be several steps ahead of those who haven’t:

• How will you hold your money? Joint account for everything? Individual accounts? A combination of both?
• Who pays for what? Have you clearly broken down your budget and how the various expenses will be covered?
• Have we separated “family expenses” from “personal expenses”? Do we agree on the breakdown?
• How will we handle major purchases? Do we have a plan to scrape together the money for our first big down payment on a house?
• Have we set up investment and retirement accounts, and what is our plan to contribute to those accounts over the long term?
• Are we prepared for retirement, even if it’s 30 years away?

Let’s not get too bogged down with the details now - these are just some examples. We’ll figure all this stuff out as we go.

This got even more fun when we had kids. 3, to be exact.

Rather than 2 incomes and a few more expenses, our balance sheet exploded. Kids’ gear, school fees, tutors, sports, lessons, doctor’s visits, and more. Family vacations went from a fun holiday to a full scale project and a major expense.

I wrote a blog about the fact that at one point, I completely lost track of my net worth. I had been keeping data in a spreadsheet, but I stopped updating it, and all the cool formulas I had written were broken.

This is a common problem - family finance is harder for several fundamental reasons:

• Multiple incomes make tracking money coming in more complicated - there are different pay days, different bonus schedules, and sometimes even different currencies.
• Multiple goals such as retirement, college funds, emergency savings, the next big family vacation, your first house down payment - they are all looking to draw down from your savings.
• Overlapping lifecycle stages - you might be paying off a student loan, saving for your kid’s college fund, and figuring out retirement care for a parent, all in the same year. That’s not easy.
• Spend is shared but may be uneven - both partners have credit cards, both can spend, but only one tends to track things - until they don’t.

This is why a lot of personal finance apps fail for families. They’re designed for one user, with one wallet, and one set of preferences. Family life isn’t shaped like that.

the joint account vs separate accounts vs hybrid question (and why there’s no right answer)

short answer: there are three common money handling models for couples - one joint account to capture everything (we call this “fully joint”), separate accounts for each partner (“fully separate”), or a “hybrid” approach - yours, mine, and ours. All three work for some families and fail for others. The right answer depends entirely on how you and your partner think about money.

Amongst couples, the joint-vs-separate question generates more arguments than almost any other money topic. The honest answer is that there is no universally correct answer here - there’s only the setup that works for you, and your particular situation.

Here are the three common models:

• Fully joint - All income flows into one shared joint account. Spending comes out of the shared account. This works when both partners have similar spending habits, are in almost total agreement on near and long term finance goals, and, of course, trust each other completely. It starts to hit roadblocks the moment one partner feels the other is judging their personal purchases, or money management.
• Fully separate - Each partner has their own accounts - nothing is shared. Shared expenses are split based on an agreement. Money is moved between shared accounts, or expenses are traded off and cancelled out. This works when both partners truly desire full financial autonomy, and have a clear mutual understanding regarding keeping their financial and personal lives separate. Things start to get dicey when one partner earns dramatically more or less, or when major shared expenses (a house, a car, a kid’s college fund) need a coordinated approach.
• Hybrid - Both partners contribute an agreed amount to a joint account that covers shared expenses. Whatever’s left in each individual account is theirs to spend. Period. This is a common modern setup, because it preserves a sense of personal autonomy, while still funding your shared family life and expenses.

Whatever model you pick, the actual system matters less than the agreement. The biggest problem in many partnerships isn’t the financial structure - it’s that the structure was never explicitly discussed and agreed.

I’ll admit - the first time I actually sat down with my wife to discuss money, I was being a bigshot. “All you need is love” is a great motto until your first real, big shared payment smacks you in the face. Then we quickly go from “Honey, don’t worry about a thing” to “Can we discuss this?” Who knows, maybe I’m alone here.

Once the reality of shared family financial planning sunk in, we agreed on a hybrid approach. We don’t have a “fixed percentage” contribution of income to our joint account, but we manage what we can every month, and that works for us. Some families like to have a very structured and fixed approach to finances, and that is fine as well.

The one takeaway from this lesson is that there is no single approach that works for everybody - but finding a lane that works for both you and your partner will save you miles of anguish down the road.

the four numbers every family should know

short answer: net worth (what you own minus what you owe), monthly cashflow (what comes in minus what goes out), runway (how many months you’d last if income stopped), and debt-to-income (how much of your monthly income goes to debt payments). Understanding these four numbers covers 90% of what most families actually need.

Almost all of the moms and dads I talk to have strong opinions about money, but are reluctant to share actual numbers. Society considers it either taboo or crass to share real numbers. Personally, I think that’s a mistake.

Obviously, this can be a touchy subject, and complicated emotions are involved. This is especially true when there are other factors, such as sibling rivalries, colleagues at the same company, competing friends, and lots of other emotionally charged situations.

However, in general I feel like it’s important to have grown-up, mature discussions about money, citing real numbers, when both parties are in full agreement. Another good way to do this is anonymously (for example - online), although this can make it harder to truly understand the other person’s situation.

If you have (or can find) a group of friends who share a genuine sense of empowerment and trust about money, this can be a great opportunity to discuss real finances and real numbers.

For most families, to truly understand your family’s financial position, you need four numbers, updated monthly:

• Net worth - Add up everything you own (savings, investments, property at current value). Subtract everything you owe (mortgage, loans, credit card balances). The result is your net worth. If it’s going up over time, you’re winning. If it’s going down, something needs attention.
• Monthly cashflow - Total income minus total spending in a typical month. Positive cashflow means you’re saving. Negative means you’re moving backwards.
• Runway - Take your liquid savings (cash, easily accessible accounts) and divide by your monthly spending. The result is how many months your family can survive with no income. For most families, this should be at least 6 months of expenses, ideally more.
• Debt-to-income (DTI) - Add up all your monthly debt (loan) payments (mortgage loan, car loan, credit cards, personal loans, etc). Divide by your monthly take-home income. Lenders commonly consider 43% the upper limit for mortgage qualification under the CFPB’s ability-to-repay rule, and many financial planners suggest keeping total DTI at or below 30% for comfort.

If you check these four numbers once a month, you’ll know more about your family’s financial reality than 80% of households.

building a simple family budget that doesn’t instantly fall apart

short answer: most family budgets fail because they’re too detailed, too restrictive, or too dependent on one partner doing all the work. A budget that survives is one both partners can agree on, and that isn’t a huge pain to update (should take 5 minutes or less on average), with broad categories and adaptability for the chaos that comes with kids.

Every year or two, I open up my old spreadsheet. I take one look at the bank account names, the balances, and all the categories of expenses I put in that one time about 15 years ago, which have now all changed.

The issue wasn’t that it was too complicated, it’s just that staring at a spreadsheet is boring, and updating your finances always feels like a chore.

After a few minutes, I’ve usually given up again, and have moved onto my next task.

What do we really need to do to make a budget work?

Based on my experience, a family budget that actually works has a few essential properties:

• Few categories - Five to ten broad categories, not fifty narrow ones. “Kids” is one category, as opposed to “school fees”, “uniforms”, “field trips”, “snacks”, and “haircuts.” I’ve found that if you determine that a certain category is hiding a problem you can subdivide it later, but keeping things simple and high level is helpful to keep both parties engaged.
• Adaptability - Reserve 10-20% of your budget for “ad-hoc stuff.” Birthday gifts, surprise repairs, a nice dinner, that new baseball glove. If your budget always assumes everything will go exactly to plan, that first month will be very disheartening.
• Joint visibility - Both partners can see the budget at any time, on their own device, without the constant “Oh, I can’t access the spreadsheet.” This is where most family budgets quietly die.
• Recurring vs one-off - Your budget should know about regular expenses (rent, school fees, subscriptions) automatically, so you’re just maintaining the recurring spend, while only really budgeting for the discretionary spend.

The two most popular budgeting frameworks for families are:

• 50/30/20 - 50% on needs, 30% on wants, 20% on savings. Simple, easy to remember, generous on the “wants” side.
• Zero-based budgeting - Every dollar is assigned to a category before the month starts. More discipline and more granularity, but also more chance of falling apart before it even gets started.

The 50/30/20 rule was popularized by Elizabeth Warren and Amelia Warren Tyagi in their 2005 book All Your Worth: The Ultimate Lifetime Money Plan. It’s popular not only because the math is memorable, but because it works well as a high level rule.

A reasonable middle ground for most families: use 50/30/20 as your high-level framework, then track a few critical categories (kids, food, big-discretionary) more carefully.

kids and money: how much do kids really cost, and what changes as they grow?

short answer: a lot. Kids’ expenses are not flat - they shift dramatically through childhood. Babies are about gear and childcare. Primary school is about activities, food, and lessons. Teens take those same expenses and push them up a notch (tutoring, devices, transport, college prep). Budget for the next stage, not just the current one.

When my first kid was born, we admittedly went a bit overboard with baby stuff, like a lot of parents probably do. Every weekend was another trip to the baby store. We bought every conceivable type of crib, baby carrier, blanket, and pillow. Then we started reading articles about how sleeping without a blanket is safer, recommending different types of setups.

The point is, we did not have a clear idea where our money was going, or why.

When our oldest was about 3 years old, he started preschool. Baby costs dropped, but a new wave of expenses moved in to fill the gap. Activities, school fees, birthday parties, field trips, and lots more. The math didn’t get easier, it just rearranged itself.

Here’s the rough shape of kid expenses by stage:

• Baby and toddler (0-4) - Childcare is the dominant cost (often 20-40% of family income in expensive cities). Baby gear can also run up a hefty bill, though most of this is one-time, and can be re-used. Healthcare is unpredictable - it can be manageable if you have insurance, but that’s a big “if”.
• Primary (5-11) - Childcare costs drop, but school fees, activities, sports, and lessons start. Food bills tick up, especially with multiple kids. Tech starts creeping in.
• Secondary (12-17) - Expenses start to increase more. Tutoring, exam prep, devices, transport, social spending, and perhaps a learner’s permit. University prep starts to become part of your everyday conversations from roughly year 13 onwards. Healthcare may also spike around adolescent years.
• Young adult (18+) - Depends heavily on whether they go to university, and whether you’re paying. If yes, this is often the most expensive 4-year stretch of parenting. After that, the costs taper, but they don’t always disappear (weddings, house deposits, grandkids).

More than anything else, the actionable insight is to budget for the next stage, not just the current one. If your kid is 8, model what your finances will look like when they’re 14. The transition catches many families off guard.

emergency funds for families - how much, and where to keep it?

short answer: while 3-6 months of expenses is standard for individuals, families should aim for the higher end (6 months), because more people and more variables means more surprises. The recommendation is to keep your savings in a high-yield savings account as opposed to invested in the market, to ensure it is always easily withdrawn when you need it (and not a day or 2 later). Don’t touch it for anything that isn’t a real emergency.

Classic personal finance advice says to keep 3-6 months of expenses in an emergency fund. For families, lean toward the higher end of that range - 6 months at least, and more if your income is variable, or you are a single-income family.

The Federal Reserve’s 2024 Economic Well-Being of U.S. Households report (SHED) found that in 2023, 37% of adults would not be able to cover a $400 emergency expense without borrowing money. That’s a serious issue, with potentially huge implications. A small buffer could be the difference between a bad week and a downward spiral.

Families have more potential failure modes than individuals - car issues, roofs leaking, medical bills, job loss, a kid that needs braces, and the list goes on. Any one of these, on its own, is a single bad month. A few of them clumped together is what can tip a family over the financial edge - which is something that we want to avoid at all costs.

A few practical notes:

• Where to keep it - I suggest a high-yield savings account, so at least you can earn a bit of interest, even if it’s in the 1-3% range. A few percent on 6 months of salary isn’t nothing - it may even pay for your next family vacation. The funds should be easily accessible, available to be withdrawn in an emergency. Avoid investing your emergency fund in the stock market - the whole point is that it’s available the day you need it, regardless of what the market is doing.
• What counts as an emergency - things like medical bills, house repairs, your car breaking down are legitimate family emergency expenses. Things like vacations, new furniture, or a new iPhone should be budgeted and planned for. Emergencies are things you literally cannot avoid paying.
• Build it before you start investing aggressively - It’s tempting to skip straight to higher-return investments, but a single bad month without an emergency fund can wipe out years of investment gains via forced selling at a bad time.

Getting stuck in a bad situation without your emergency fund is what can cause financial hardship and panic, from which it can be hard to recover. While the run-up to building your emergency fund can be challenging, if and when you need to use it, you’ll be glad it’s there.

the dreaded “money conversation” with your partner

short answer: the most useful family finance habit isn’t a budget app or a spreadsheet - it’s a 30-minute conversation with your partner. It may happen once a month, or once every couple months, with the four important numbers we discussed above in front of you. The conversations should be structured, calm, and ideally not at the end of a long and stressful day.

The best thing you can do for your family’s financial health (and sometimes the most challenging) isn’t picking the right app or index fund - it’s having a regular, structured conversation with your partner about money.

A lot of couples only talk about money when something goes wrong, or a big purchase needs to be made. Deferring these important conversations for these uncommon occurrences is a recipe for conflict. Don’t wait until you need to buy a new house, or a credit card bill is bigger than expected, or a partner finds out about a purchase the other made. By the time the conversation happens, it’s reactive and emotional.

A monthly money meeting changes the pattern. Here’s a workable format:

• Schedule it - have the meeting at the same time every month, at a time when both of you are calm and not exhausted. Keep it to 30 minutes max.
• Open with the four numbers - net worth, monthly cashflow, runway, debt-to-income. Rather than discussing anything yet, just look at them together.
• Talk about what’s coming up - Are there any big expenses coming up in the next 30-60 days? Trips, birthdays, bills you’re expecting, etc. Discuss anything that needs a decision.
• Talk about what surprised you - Discuss anything in the last month that was bigger or smaller than expected, and why. Try to catch slow-moving problems before they become big.
• End with one decision - What’s the one thing you’ll do differently next month?

Two big rules:

• No blame - whoever overspent, whoever forgot something, it doesn’t matter. The only useful question is, “What do we do next?”
• No surprises - If you make a big purchase between meetings, mention it before the meeting. Avoid having the meeting be the place where the other person finds out about something.

Keep at it. If you can do this for six months, you’ll know more about your shared finances than the average couple knows after a decade.

managing family finances across multiple currencies (for expats and global families)

short answer: expat and global families have a different set of concerns bolted on top of the existing family finance issues. We need to manage currency risk, local and foreign taxes, and for those of us running a business, multiple rules and regulations regarding business and corporate finance. Managing this can be a challenge, but it’s possible with the right support.

If you’re an expat family, or even a domestic family with international ties (for example, you have a business investment overseas, kids studying abroad, in-laws in another country, income in a foreign currency, etc.), your finances are a meaningfully different problem than a family with only domestic finances to worry about.

Some structural challenges multi-currency families deal with:

• Income in one currency, costs in another - When the exchange rate moves, your real income moves with it. A 10% currency swing can make a meaningful difference to your take-home income.
• Bank accounts in multiple jurisdictions - Each country comes with its own rules, fees, and friction. Moving money between countries is rarely free.
• Dual or multi-tax exposure - Depending on your nationality and residency, you may owe taxes in two countries on the same income, or at least be required to file multiple returns.
• Kids in international schools - School fees may be denominated in one currency, but your salary in another. School fees are usually paid annually or semi-annually, which can compound foreign currency risk.
• Family back home - Sending money to parents, relatives, or extended family across borders is a recurring expense that most family finance guides never mention.

Tools that help:

• Multi-currency accounts (Wise, Revolut) - Hold balances in multiple currencies, exchange currencies when rates are favorable, transfer at near-interbank rates, and avoid the brutal markup that most banks charge.
• A tracking system that handles multiple currencies natively - Most personal finance apps assume one currency. The few that handle multi-currency well do it by storing each transaction in its original currency, and converting on display.

When I first started working in Japan I was paid in JPY, which was convenient. I could pay for my local everyday expenses, but I needed to convert money any time I travelled back to the US. When my company gave me the option to be paid in USD, I jumped on it, thinking holding money in USD would be beneficial. It was one of the worst financial decisions of my career.

The JPY was having a historically strong bull run against the dollar, and that one decision cost me anywhere from 10-30% of my take-home income every month, versus being paid in yen. While the decision to be paid in USD may have been beneficial for somebody who spent more time overseas, for me, it was the wrong decision and an expensive lesson to always do your homework before making a major financial decision.

I built beanies.family specifically to help with families dealing with multiple currencies. Using beanies.family helps me immensely to view my finances, held in USD, SGD, and other currencies (hi there, crypto traders!). It’s useful being able to see my net worth in any currency, and to capture my expenses in the currency that I pay, rather than having to convert it myself.

how and when to teach your kids about money

short answer: start younger than feels comfortable - preschoolers can grasp that “things cost money” and some pre-schools even teach counting using coins as a prop. Primary school-aged kids can manage a small allowance. By their teens, they should be involved in real conversations about finances and how the family makes decisions. Money skills are learned by watching how parents handle it more than through formal lessons.

The most useful financial education your kids will receive is the one happening in the background of your daily life - how you and your partner talk about money. Kids will hear about how you handle a tight budget, a bad month, how you celebrate a windfall, and how you make spending decisions - even if you think they’re not listening. Those are the lessons they actually absorb, regardless of what you say.

That said, here’s a rough age-by-age framework for explicit money lessons:

• Ages 3-5 - “Things cost money, and money is earned from work. We can’t have everything we want.” Keep the lessons concrete and simple, using examples they understand. Letting them hand real money (ideally) to a cashier, and getting back change, is a fun way to get them involved.
• Ages 6-10 - This is a good time to start with a small allowance. Help them divide it into spend / save / give. A visit from the tooth fairy is a nice windfall to add to their stash. Let them make small spending mistakes (overpriced toys at the mall) and feel the consequences.
• Ages 11-14 - At this point, you can open a basic savings account in their name. Talk about why interest exists, and introduce the concept of “lifetime cost” - the streaming subscription which is only $10/month will cost $6,000 over 50 years (in nominal dollars - if you invested that $10/month instead at 7% returns, it’d be closer to $50k).
• Ages 15-18 - Bring your kids into real family financial conversations, within reason. Show them the rough shape of how the household budget works. Talk about the trade-offs related to actual decisions they may need to make in college.
• Ages 18+ - Help them open a bank account. I’d recommend a debit card rather than a credit card, even if they clearly understand the disastrous financial consequences of being saddled with high-interest credit card debt. It’s better to be safe than sorry. This is the age where lifelong habits get set.

If you want to run the numbers yourself or together with your kids, the SEC’s compound interest calculator at investor.gov is free, authoritative, and easy to use. Just plug in your contribution, rate, and timeline, and see how the curve steepens.

My 10-year-old picked up the concepts early on, and even used his own money to buy his favorite Dog Man books at the local book store. Using his money to buy something he wanted was a great way to get him engaged, and to have a discussion about money and savings.

tools that help, and tools that lock you in

short answer: most family finance tools are designed for personal use, and bolt on family features as an afterthought. The right tool for your family is one that handles multiple people, several accounts, foreign currencies, and gives you a clear shared family view, without locking your data into a format you can’t escape.

A few common tool categories, with honest pros and cons:

• Spreadsheets (Excel, Google Sheets) - Maximum flexibility, minimal lock-in, free. But also, minimal guidance and direction - everything is up to you. They require manual updates, and only the spreadsheet owner maintains them. Spreadsheets degrade fast once kids enter the picture.
• Mainstream personal finance apps (Mint, YNAB, Copilot Money) - Polished app / user interface, automatic bank transaction sync, useful budgeting features. They’re often designed for one user, and store your data in their cloud (with the privacy implications I covered in the local-first guide). While it’s unlikely, your data disappears if the company shuts down. Mint is the cautionary tale here - millions of users and data, then suddenly it was gone.
• Online banking / bank-specific tools - These are typically free and well-integrated with your bank. The issue is that they only see the accounts you have at that bank, and typically have weak family / multi-user support.
• Local-first family and finance planning tools - This is where beanies.family comes into the picture. Your data stays on your device, fully encrypted, and family-aware from the ground up. The trade-off is that there is a smaller ecosystem with banks, meaning manual entry instead of bank sync. For some (like me), this is a plus.

Pick a tool that supports the way your family actually operates - multiple people, shared visibility, multi-currency if you’re international, and make sure your data can be exported in a real and readable format. If the answer to “can I get my data out?” is no, run.

For more on why data ownership matters, see the companion guide: what is local-first software.

if you only remember three things

short answer: know your four numbers, hold a monthly money meeting with your partner, and use a tool you trust. When it comes to family finance, these three habits will put you several steps ahead of the game.

We’ve covered a lot here. If you take nothing else away:

• Know your four numbers - Net worth, monthly cashflow, runway, debt-to-income. Update them once a month and you’ll know more than 80% of families.
• Hold a monthly money meeting with your partner - 30 minutes, structured, and calm. The single highest-leverage thing you can do for your family’s financial health.
• Use a tool you trust - Wherever you track your family finances, whether it’s a spreadsheet, app, or ledger, make sure your data is yours and exportable. The tool you love today may not exist in five years.

Family finance is hard, and the systems that work aren’t necessarily the most sophisticated ones - they are the ones that both partners actually use. Build for that, and you will come out ahead.

If you want to learn more, or just want to read more of my dumb writing, join the beanstalk on substack for a weekly-ish letter from me.

And if you want to try a family-aware tool I built precisely because none of the existing ones worked for me, that’s beanies.family.