Currency Exchange Calculator Formula
Understand the math behind the currency exchange calculator. Each variable explained with a worked example.
Formulas Used
Converted Amount
converted = (amount - fee_amount) * exchange_rateFee Cost
fee_cost = fee_amountEffective Exchange Rate
effective_rate = (amount - fee_amount) * exchange_rate / amountVariables
| Variable | Description | Default |
|---|---|---|
amount | Amount to Convert(USD) | 1000 |
exchange_rate | Exchange Rate (per 1 USD) | 0.92 |
fee_pct | Exchange Fee(%) | 2.5 |
fee_amount | Derived value= amount * fee_pct / 100 | calculated |
How It Works
How Currency Exchange Works
Multiply your amount by the exchange rate to convert. Exchange providers charge a fee (percentage or markup on the rate).
Formula
Converted = (Amount - Fee) x Exchange Rate
Effective Rate = Converted / Original Amount
Worked Example
Convert $1,000 USD to EUR at 0.92 rate with 2.5% fee.
- 01Fee = $1,000 x 2.5% = $25.00
- 02Net amount = $1,000 - $25 = $975
- 03Converted = $975 x 0.92 = 897.00 EUR
- 04Effective rate = 897.00 / 1,000 = 0.8970
Frequently Asked Questions
Where do I find current exchange rates?
Check Google, XE.com, or your bank for mid-market rates. The rate you actually get will be slightly worse due to the provider's markup.
What is the cheapest way to exchange currency?
Use a no-foreign-transaction-fee credit card, withdraw from ATMs abroad with a fee-free bank, or use services like Wise. Avoid airport exchange kiosks.
What is the mid-market rate?
The mid-market rate is the midpoint between buy and sell prices on the global market. It is the fairest rate; any difference is the provider's markup.
Ready to run the numbers?
Open Currency Exchange Calculator