Currency converter
Offline by default: type the rate yourself and convert between 30 currencies with exact integer arithmetic on the smallest unit. When you want live rates, click “Fetch latest rates” to pull one snapshot from the ECB reference rates (Frankfurter); a failure keeps your manual rate and explains why.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Conversion settings
Offline by default: you supply the rate. A public rate API (Frankfurter, ECB reference rates) is called only when you press “Fetch latest rates”, and a failure keeps your manual value.
Result
7.2720.00 CNY0.00 CNY720.00 CNYEntered manuallyWhat this tool does
- Offline conversion: on a plane or in a meeting without reliable network, type one rate and convert without handing your amounts to an online service.
- Use your own rate: enter the rate your bank or payment platform actually gives you, which is closer to the money you receive than a mid-market quote.
- See the net after fees: put in a 1% or 2% fee and see exactly how much of the target currency you keep.
- Fetch a reference rate when you want one: one click pulls an ECB reference snapshot instead of looking it up by hand.
Example
Input
From USD, to CNY, amount 100, rate 7.2, fee 0%
Output
Rate used 7.2, converted amount 720.00 CNY, fee 0.00 CNY, after fee 720.00 CNY, rate source: entered manually
Everything runs on integer minor units: USD 100 becomes 10000 cents, times 7.2 gives 72000 cents, i.e. 720.00 — no floating-point rounding along the way.
Frequently asked questions
Does this tool call the network by itself?
No. It is offline by default — you supply the rate and the page makes no requests. A public API (Frankfurter, based on ECB reference rates) is called only when you press “Fetch latest rates”, and the result is written back into the rate field.
What happens if fetching rates fails?
The page explains why (no network, rate limiting or an unexpected response shape) and keeps the rate you typed, so the conversion never goes blank or wrong. Retry later or keep using your manual rate.
Why do online rates differ from my bank’s?
ECB reference rates are mid-market quotes that exclude spreads, fees and cross-border charges. A bank’s buying rate is typically 0.3%–1% worse, and card networks add a conversion fee on top, so what you receive is slightly less.
How are currencies without decimals handled?
Each currency keeps its own smallest unit: USD, CNY and EUR use two decimals while JPY, KRW, VND and IDR round to whole units. Results are rounded to the target currency’s precision, so you never see half a yen.
Which currencies are supported?
Thirty common currencies, including USD, EUR, CNY, JPY, GBP, HKD, TWD, KRW, SGD, AUD, CAD and CHF. The online API covers only a subset, so enter the rate manually when a quote is missing.
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