If you have ever tried to calculate your net worth when your savings are in euros, your brokerage is in US dollars, and your old bank account is in Vietnamese dong, you know the problem: which rate do you use, and how do you update it every month?
This post walks through the practical mechanics of multi-currency net worth tracking — what to track, how to handle exchange rates, and how to think about the number you get at the end.
Choose one base currency
The first decision is the most important: pick a single base currency for your net worth total. This should be the currency you think in, the one you plan retirement in, or the one your primary income arrives in.
Most people use their home country currency or the currency of their largest account. If you are an expat with income in EUR but planning to retire in Vietnam, you might use EUR as your base and show VND as a secondary display.
The base currency is just a lens. It does not mean your other accounts are less real — it means you have a stable unit to measure growth over time.
Record native amounts; convert at entry time
The most accurate approach is to record each account balance in its native currency, then apply an exchange rate at the time of entry.
For example, in April you have:
- ING savings: €24,500 (native: EUR)
- Fidelity brokerage: $18,200 (native: USD, rate: 1 USD = 0.92 EUR → base: €16,744)
- Techcombank: ₫420,000,000 (native: VND, rate: 1 VND = 0.000038 EUR → base: €15,960)
Your total: €57,204
Next month the dollar strengthens. Your Fidelity balance barely moved in USD, but its EUR equivalent increases. That shows up correctly in your chart without any extra work on your part.
Where to get exchange rates
For monthly net worth tracking, precision to three significant figures is enough. You do not need a live feed.
Good sources for a monthly snapshot:
- Google — search "USD to EUR" for the current mid-market rate
- XE.com — historical rates if you want to backfill old data
- Your bank's app — if you transferred money that month, use the rate you actually got
Record the rate you used each month. If you ever want to audit why a particular month looks odd, you can check the rate column.
Handling volatility
Multi-currency net worth will move more than a single-currency tracker, even when your actual account balances are flat. A 3% swing in EUR/USD over a month shows up directly in your total.
A few strategies to keep this from being distracting:
Don't obsess over month-to-month currency noise. Focus on 3-month and 12-month trends instead. Short-term FX moves average out.
Track the native balance separately. Seeing that your Fidelity balance grew from $18,200 to $19,100 in USD is a real achievement, even if the EUR equivalent barely moved due to a weak dollar.
Add a secondary currency display. If you have family or obligations in another country, showing your net worth in two currencies simultaneously helps you stay grounded in both realities.
Handling accounts you rarely update
Some accounts — illiquid investments, a property, a pension — don't change month to month. It is fine to carry forward the same balance with the same exchange rate. Just update it when you get a new statement.
The key is to keep the account in your tracker even when you have nothing new to enter. An empty month (no new statement) is different from an account you forgot about.
What the final number means
Your multi-currency net worth in base currency is an approximation. It tells you: "if I liquidated everything today and converted it to EUR, I would have roughly this much."
That approximation is useful for tracking growth over time, measuring progress toward goals, and understanding how your total responds to market and currency events. It is not a guarantee of what you would actually receive in a liquidation scenario — fees, taxes, and spread would all apply.
Used consistently with the same methodology, month after month, the number becomes a reliable compass. That consistency is worth more than any single-decimal precision.
Fizzy handles multi-currency accounts natively. Each account records its native currency and you enter an exchange rate at monthly entry time. The base currency total and secondary display update automatically. Try it free →