Currency Converter

The European Central Bank's daily reference rates, served by the open Frankfurter API — the same official rates used for accounting, invoicing, and financial reporting across Europe. They're published once per working day around 16:00 Central European Time, so weekend and holiday queries return Friday's rates. The publication date is shown under every conversion, because a rate without its date is half an answer.

Because this is the mid-market reference rate — the midpoint between buy and sell — and every real-world exchange adds a spread around it. Banks and card networks typically take 1–4%, airport kiosks far more, and 'zero commission' services hide the fee inside a shifted rate. The practical use of the reference rate is as a measuring stick: compare any quoted exchange against it, and the gap is what you're actually being charged.

Usually it's exactly right — ECB reference rates are the conventional standard for cross-border invoices, expense reports, and many tax computations, precisely because they're official, dated, and reproducible (a given day's rate never changes retroactively). For US tax purposes the IRS accepts any consistently applied posted rate, and yearly average rates for some cases. What reference rates aren't for: pricing live trades, which happen at market rates with spreads.

Currency convention, not rounding laziness: yen, won, rupiah, and a few others have no commonly used subunit, so real-world amounts are whole numbers — a price of ¥1,524.37 doesn't exist in practice. The converter formats each currency the way its own country writes money. The underlying math keeps full precision; only the display follows convention, so converting back and forth doesn't accumulate rounding drift.