Finance

Currency Converter

Enter an amount, pick a source and target currency, and see the converted value with the cross-rate and rate date. Rates update on business days from official sources via Frankfurter.

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Daily reference rates from central banks (Frankfurter) — not live trading, bank, or card rates. Fees and spreads are not included.

Updates as you type

The formula

Cross-rates are derived from EUR-based reference rates: converted = amount × (rate_to ÷ rate_from), where each rate is how many units of that currency equal one euro.

Converted = Amount × (EUR→To rate ÷ EUR→From rate)

Worked example

  1. 100 USD → EUR (example rates)
  2. 1 EUR = 1.14 USD, so 100 USD ÷ 1.14 ≈ 87.72 EUR
  3. Cross-rate shown: 1 USD ≈ 0.877 EUR

Result: ≈ €87.72 (rate date shown in result)

How currency conversion works here

We use Frankfurter, an open-source API that aggregates daily reference rates from central banks. This is ideal for travel estimates and general comparisons — not for executing trades or bank transfers.

EUR as the pivot

Frankfurter publishes rates against the euro. To convert USD → GBP, we first express the amount in EUR, then convert to GBP. Mathematically: amount × (GBP rate ÷ USD rate).

Update schedule

Reference rates are typically updated once per business day, around 16:00 CET. Weekend and holiday values reflect the last working day. The result badge shows the rate date.

What we do not model

No buy/sell spreads, ATM fees, card FX markups, or crypto. Banks and payment providers quote different prices than central-bank references.

Supported currencies

All ISO currencies currently available from Frankfurter (~165) appear in the dropdowns — major units such as USD, EUR, GBP, JPY, CHF, CAD, AUD, and TRY, plus regional currencies worldwide.

Interesting facts

Reference vs retail rate

Banks and card networks add a spread on top of central-bank reference rates. A 2–3% markup on foreign card purchases is common — your checkout total may differ from this tool.

Open reference data

Frankfurter aggregates daily rates from central banks and publishes them as open data — free to use, no API key required.

Business-day updates

Reference rates refresh on working days (around 16:00 CET), not continuously. Weekends and holidays show the last available business day.

Frequently asked questions

From Frankfurter (frankfurter.dev), which aggregates daily reference rates published by central banks. Rates are updated on business days, not in real time.

Every currency Frankfurter currently publishes — about 165 ISO codes, including USD, EUR, GBP, JPY, CHF, CAD, AUD, TRY, and many regional units.

Usually not exactly. Banks and cards apply their own spread and fees. Use this for estimates; compare your provider’s quote for the actual transaction.

Enter the dollar amount, choose USD as “From” and EUR as “To”. The result uses the latest Frankfurter reference cross-rate and shows the rate date.

Markets are closed on weekends and some holidays. Frankfurter keeps the last working day’s reference rates until the next update (~16:00 CET on business days).

References

  1. Frankfurter — free exchange rates API — Frankfurter (open source) Daily reference rates from central banks; data source for this calculator.
  2. ECB euro foreign exchange reference rates — European Central Bank Primary source for many EUR cross-rates in Frankfurter.