About our rates

Last updated 21 September 2026

What the rates are

FX Calc shows indicative mid-market reference rates: the midpoint between buying and selling prices in wholesale currency markets. They are for information and planning. They are not quotes or offers to exchange money.

Where they come from

Rates are currently provided by Exchange Rate API. Every rate is expressed as units of currency per one US dollar, and conversions between any two currencies are calculated from those USD rates.

How often they update

Our servers check for new rates every hour, and the provider currently publishes new rates once a day. Every page and the app show the time the rates were last updated. Rates change less over weekends and market holidays, when major markets are closed.

How we check them

Before publishing, we validate every rate: each must be a positive number, all major currencies must be present, and any large unexpected move is held back. If an update fails these checks, we keep showing the last rates that passed.

Why your bank's rate is different

Banks, card networks, money transfer services, and cash exchangers usually add a margin to the mid-market rate, charge a fee, or both. The amount you actually pay or receive will normally be less favourable than the rate shown here.

How we calculate

Conversions use exact decimal arithmetic and are rounded only for display, using each currency's standard number of decimal places. Very small results keep extra significant digits so they never show as zero.