CURRENCY CONVERSIONS
February 10, 2026 ยท View on GitHub
SplitPro can convert expenses and balances between currencies using cached exchange rates.
What you can do
- Display balances in a single currency.
- Convert an individual expense into another currency.
- Convert group balances on the fly from the balance view.
- Edit existing currency conversion transactions.
How conversions work
- Rates are fetched from the configured provider and cached in the database.
- Conversions can be created for an expense and later edited if needed.
- Group balances can be converted on demand without changing the original expense currency.
Providers and limitations
Exchange rate APIs are typically rate limited or paywalled. SplitPro supports three providers and caches results in the database to reduce API usage.
- Frankfurter (https://frankfurter.dev/)
- Free, but limited currency set.
- Check availability at https://api.frankfurter.dev/v1/currencies.
- Open Exchange Rates (https://openexchangerates.org/)
- Free tier includes 1000 requests/day and wide currency coverage.
- Free tier uses USD as the base currency; SplitPro joins rates internally.
- Requires an API key.
- NBP (https://api.nbp.pl/en.html)
- Polish National Bank.
- No API key required, base currency PLN.
- Table A updates daily, table B (less common currencies) updates weekly.
Provider comparison
| Provider | Base currency | Coverage | API key | Notes |
|---|---|---|---|---|
| Frankfurter | EUR | Limited | No | Free, limited currency set |
| Open Exchange Rates | USD | Broad | Yes | Free tier 1000 req/day |
| NBP | PLN | Medium | No | Table B updates weekly |
Configuration
Set your provider in CURRENCY_RATE_PROVIDER and supply OPEN_EXCHANGE_RATES_APP_ID if you use Open Exchange Rates. See CONFIGURATION for all related variables.
Notes
- Rates are cached in the database to minimize calls and stay within provider limits.
- Provider coverage and rate freshness depend on the selected provider.
Common use cases
- Display all balances in your home currency.
- Convert a foreign receipt into the group currency.
- Compare group balances across multiple currencies.
UI walkthrough videos
- Expense conversion: https://github.com/user-attachments/assets/95ab9a6b-44da-419e-a7ee-d6314af37d03
- Group balance conversion: https://github.com/user-attachments/assets/63b62b2b-be0f-4fe4-9be9-e30b5caaaf06