To budget with income in multiple currencies, build the budget in the currency you spend, count every foreign payment at a planning rate a little worse than today’s, and split each payment the day it lands, in the currency it arrived in. Then convert once a month on a fixed day, not whenever the news gets loud. While the real rate stays above your planning rate, the plan holds even if the rate slips, and the difference goes to your buffer.
A planning rate is the exchange rate you budget with: one fixed number, set below today’s rate and reviewed once a quarter, so a weak month for your income currency doesn’t break your plan.
This is for anyone paid in a currency they don’t spend: a designer in Lisbon with US clients, a developer in Warsaw paid in euros, a creator whose platform pays out in dollars.
Which currency should your budget be in?
Budget in the currency your bills are in. Rent, groceries, utilities and transport are priced in local money, and they don’t care what the dollar did this week. Your income is the part that moves, so that’s where the risk belongs, and that’s where a margin can absorb it.
Budget in dollars while you pay rent in euros and every month looks different on paper, even when you spent the same. Months stop being comparable, and you lose the one thing a budget is for: seeing what changed.
If you’re unsure, pick the currency you spend at least half your money in and stick with it. Two exceptions:
- A bill in your income currency. If your rent, a loan or a work tool is billed in dollars, keep that line in dollars and pay it straight from dollar income. No conversion, no rate risk.
- You move between countries. Then budget in the currency you earn, and treat each place’s costs as a converted line.
How do you pick a planning rate?
Five steps, about ten minutes, once a quarter:
- Find the rate you actually get. Use the rate your bank or payment service gives you when it converts, after its fees, not the mid-market rate from the news. The gap between the two is part of your cost.
- Look back 12 months. Find the weakest rate of the year for you: the day your dollar bought the fewest euros.
- Take the lower of two numbers: that weakest rate, or today’s rate minus 5%.
- Round it down to something you can multiply in your head.
- Write it down and leave it alone for three months. Review it on a fixed date, not after a scary headline.
If you’re unsure, plan about 10% below today’s rate. That covers a weaker rate and fees at once, and if the rate barely moves, you end up with extra money instead of a gap.
Change the planning rate early in one case only: when the real rate drops below it. Then your plan counts money that won’t arrive, so lower it the same day.
How big should your exchange-rate margin be?
The margin is the gap between today’s rate and your planning rate. Here is what it does with every $1,000, if today $1 converts to €0.90 for you (an example, not a forecast):
| Planning rate | Margin below €0.90 | $1,000 in your plan | Extra per $1,000 if the rate holds | When it fits |
|---|---|---|---|---|
| €0.90 | 0% | €900 | €0 | Never: the first dip breaks the plan |
| €0.85 | about 6% | €850 | €50 | The rate hardly moved over the past year |
| €0.80 | about 11% | €800 | €100 | You’re unsure: start here |
| €0.75 | about 17% | €750 | €150 | The rate swung hard, or your income is irregular too |
The extra isn’t lost: it lands in your buffer or goes to a goal. The price of a bigger margin is a tighter plan today. Too small and one bad month breaks the plan; too big and the plan starts to feel like a punishment. Pick the smallest row you can live with calmly.
The extra column assumes no fees. Real conversions take a cut, so expect a little less.
In what order should you split a payment in another currency?
The same order as any income, with two additions: you record what arrived, and you split before you convert.
- Record what actually arrived. After platform and transfer fees, not the invoice amount. A $2,000 invoice that lands as $1,950 is a $1,950 income.
- Set the tax share aside the same day, if you’re self-employed. How foreign income is converted for tax depends on your country, so check with an accountant. More in setting money aside for taxes.
- Split the rest in the currency it came in. With a 10/20/10/60 split that’s 10% savings, 20% debt, 10% partner and 60% living. Here’s how 10/20/10/60 compares with 50/30/20.
- Count the living share at your planning rate. That’s the number your monthly budget sees.
- Convert once a month, on a fixed day. Convert the living share into your buffer, which pays your salary in local money. The other pockets wait in the currency they came in.
Keeping two currencies straight by hand is where spreadsheets tend to fall apart. In Tenfold for iPhone, each account keeps its own currency: you say "got paid $1,950 for the app design", the income splits into pockets by your rules, and converting dollars to euros is a transfer between two accounts that records what you sent and what arrived.
When should you convert, and how much?
On a schedule, and only what you’ll spend in local money. A fixed day takes the guessing out: nobody knows whether today is a good day. Waiting for a better rate is a bet, and your rent shouldn’t depend on one.
- Living money: once a month, the whole living share. It goes into your buffer, and the buffer pays bills, so keep it in their currency.
- Goals: keep the money in the currency the goal is priced in. A trip to New York stays in dollars; a laptop you’ll buy locally gets converted on the day you buy it.
- Emergency fund: it exists to pay bills, so keep at least one month of it in the currency your bills are in. More on sizing it in how much an emergency fund should be.
- The other pockets: savings, debt and partner money can wait in dollars. Convert a part only when a payment in euros is due, like a loan installment.
What does one quarter look like with a planning rate?
Marco is a developer in Lisbon. His US clients pay in dollars, his life costs euros, and his lean month comes to €1,600, so that’s the salary he pays himself. Today $1 gets him €0.90. He takes the default from the table, about 10% below, and rounds down to a planning rate of €0.80. At that rate his €1,600 salary needs $2,000 of living money a month.
He splits every payment 10/20/10/60 in dollars (amounts after the tax share, to keep the math simple). His buffer is in euros, since it pays his salary, so at the end of each month he converts the whole living share into it:
| Month | Paid in | Living share (60%) | In the plan at €0.80 | Rate he got | Euros he got | Extra |
|---|---|---|---|---|---|---|
| January | $3,000 | $1,800 | €1,440 | €0.90 | €1,620 | €180 |
| February | $2,000 | $1,200 | €960 | €0.85 | €1,020 | €60 |
| March | $5,000 | $3,000 | €2,400 | €0.85 | €2,550 | €150 |
| Quarter | $10,000 | $6,000 | €4,800 | €5,190 | €390 |
His plan counted €4,800, exactly three months of salary. The rate slipped from €0.90 to €0.85 and the plan didn’t notice. His buffer covered February’s thin month, the way it does with any irregular income, and by the end of March it was €390 fuller than at the start.
Had he planned at January’s €0.90, he’d have counted €5,400 and come up €210 short. The other 40% stayed in dollars until needed: $1,000 for savings, $2,000 toward the loan and $1,000 for his partner.
FAQ
Should I budget in the currency I earn or the one I spend?
In the one you spend. Your bills are fixed in that currency, so the plan stays steady and only the income side moves. Budget in your earning currency only if your costs are spread across several countries.
How often should I update my planning rate?
Once a quarter, on a fixed date. Lower it straight away if the real rate falls below it, because then your plan counts money that won’t arrive.
Do conversion fees belong in the planning rate?
Yes. Start from the rate you actually get after fees, not the mid-market rate, so the plan matches the money that really reaches your account.
What if I’m paid in three or more currencies?
Keep one budget currency and give each income currency its own planning rate. Review them all on the same day each quarter, and split every payment the day it lands, whatever currency it’s in.