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CalculatorBuddy

Currency Calculator

Convert between currencies with a live mid-market exchange rate, or enter a custom rate. See the reverse conversion and the rate date and source.

Live exchange rate

ExampleSample values — edit any field to see your result.

Results update as you type.

Converted amount

100 USD = 86.0364 EUR

Estimated result

Reverse
100 EUR = 116.22987 USD
Rate used
1 USD = 0.86036 EUR
Source
As of September 8, 2026 · ExchangeRate-API
Converted amount100 USD = 86.0364 EUR

Convert an amount from one currency to another with a live mid-market exchange rate, or type your own rate. The calculator also shows the reverse conversion so you can read the quote in either direction.

Formula

The live and custom modes use the same relationship. The rate is units of B per 1 unit of A:

Forward  = amount × rate
Reverse  = amount ÷ rate

At a rate of 4, 100 A = 400 B and 100 B = 25 A.

Live rates are mid-market snapshots, not the bid or ask a bank or airport kiosk will give you. They update about once a day from ExchangeRate-API. Bitcoin is not listed — the provider has no crypto quotes.

Popular currencies

The default list matches the most-traded codes (USD, EUR, JPY, GBP, AUD, CAD, CHF, and others). Uncheck Show most popular currencies only for a larger fiat list. Commodity tickers such as gold are skipped.

CodeCurrency
USDUS Dollar
EUREuro
GBPBritish Pound
JPYJapanese Yen
AUDAustralian Dollar
CADCanadian Dollar
CHFSwiss Franc
CNYChinese Yuan

Examples

Custom rate of 4 B per 1 A

With 100 units of A and a rate of 4, the conversion is 100 × 4 = 400 B. The reverse line is 100 ÷ 4 = 25 A.

Reading a live USD to EUR quote

If the live rate is 0.85 EUR per 1 USD, then 100 USD converts to 85 EUR, and 100 EUR converts back to about 117.65 USD. The result panel shows the rate date and that the source is ExchangeRate-API.

Frequently asked questions

How do I convert one currency to another?
Multiply the amount by the exchange rate expressed as units of the target currency per 1 unit of the source currency. At 4 B per 1 A, 100 A converts to 400 B. The reverse conversion divides by the same rate: 100 B is 25 A.
What exchange rate does the live mode use?
Live mode uses a mid-market rate from ExchangeRate-API's free daily feed (open.er-api.com), quoted as units of the target currency per 1 unit of the source. Banks, airports, and brokers add a bid-ask spread, so the cash you receive will differ. The result panel shows the rate date and source.
Why isn't Bitcoin on the currency list?
The free live-rate provider covers fiat currencies only. Bitcoin and other cryptocurrencies are omitted. Use Custom rate if you have a BTC quote from another source.
What is a currency pair?
A quote of one currency against another. The first is the base (always 1 unit) and the second is the quote currency. EUR/USD 1.10 means one euro is worth 1.10 U.S. dollars. This calculator's rate field is the same idea: units of B per 1 unit of A.
Should I exchange money at home or abroad?
It depends on the destination, but exchanging at a bank or credit union before you travel often beats airport kiosks, which typically post the widest spreads. Credit and debit cards that waive foreign-transaction fees usually track closer to the mid-market rate this calculator shows.

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