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Currency Converter

Convert between world currencies using free European Central Bank rates via the Frankfurter API, with a 30-day historical trendline.

target = amount × rate(from→to)

Amount From To

Frequently asked questions

Where do the exchange rates come from?

From the Frankfurter API (api.frankfurter.app), a free open service that publishes European Central Bank reference rates. NumberCals does not own or operate it. Rates are ECB business-day figures and can differ from real-time market and retail prices.

Can you show a worked example?

If 1 USD = 1.52 AUD, then 100 USD × 1.52 = 152 AUD. The converter simply multiplies your amount by the live fetched rate.

How do I read the trendline?

The chart plots the exchange rate over the last 30 days, so you can see whether the pair has been strengthening, weakening or holding steady before you convert.

What happens if the rate service is offline?

The calculator never crashes — it shows an amber warning banner and a message that currency data is temporarily unavailable, and asks you to try again shortly.

Should I rely on this for trading or large transfers?

No. These are reference rates for general information only, not financial advice. Banks and brokers add spreads and fees, so confirm the actual rate with your provider before committing to a transaction.