Different currencies, one clear split

Enter each expense in the currency it was paid in. Choose one currency for the final balances. SplitSeas requests a dated Frankfurter reference rate for each needed currency pair and expense date.

A USD and MXN trip

Ana paid USD 200 for a hotel and Ben paid MXN 1,000 for dinner on January 6, 2025. Ana, Ben, Cam and Dan shared both equally, with balances in USD.

The checked historical Frankfurter rate is 1 MXN = 0.04881 USD, requested and effective January 6, 2025. Dinner converts to USD 48.81, making the total USD 248.81. Ana gets back USD 137.79. Ben pays Ana USD 13.39; Cam and Dan each pay Ana USD 62.20.

This is a historical worked example, not today's exchange rate. Select Try an example in the calculator to reproduce it against the provider.

Check both dates

The expense date is the requested date. The effective date is the date of the reference rate returned by the provider. These can differ when no rate is available for the requested day. The results show both dates, the rate and the provider. Missing or invalid rates stop the calculation with an error; no substitute rate is invented.

How rounding works

Each expense converts once and rounds half up to the balance currency's minor units. Integer minor units and exact fractions keep calculations consistent. Shares use largest fractional remainders, with participant order breaking ties, so the shares always equal the converted total.

Supported currencies

USD, MXN, EUR, GBP, CAD, AUD, CHF, JPY, KRW, KWD, INR, BRL, NZD and SGD. JPY and KRW use whole units; KWD uses three decimal places; the others use two. Rates depend on provider availability for the pair and date, from January 4, 1999 through today.

Reference rates are not bank quotes

Card spreads, bank charges and payment-provider fees are excluded. If your group agrees to use an actual card charge, enter that charged amount as an expense in the charged currency. SplitSeas does not trade currencies or move money.

Read more worked examples or ask for a split in ChatGPT when the integration is available.