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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.

Maintained by CalculatorBuddy TeamEditorial methodology

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Live exchange rate

ExampleSample values — edit any field to see your result.

Results update as you type.

Converted amount

100 USD = 88.9517 EUR

Estimated result

Reverse
100 EUR = 112.42056 USD
Rate used
1 USD = 0.88952 EUR
Source
As of October 17, 2026 · ExchangeRate-API

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Compare scenarios

Keep a baseline, then change an assumption to see its effect side by side.

Converted amount100 USD = 88.9517 EUR

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

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.

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 provider reference 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.

Rate timing and limits

The result displays the provider's rate date and source. The application briefly caches a daily reference snapshot, so it is not a streaming tradable quote. Financial institutions, cards, transfer services, and cash exchanges may use different timestamps and add spreads or fees. Use Custom rate with the provider's final quote when the exact delivered amount matters.

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 reference 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?
Compare the provider's all-in amount after its exchange spread, transfer or card fees, ATM charges, and any dynamic-currency-conversion markup. The reference rate here does not include those costs.

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