Calculate currency cost

Expose the exchange-rate spread and flat fee inside a foreign-currency purchase or transfer.

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ToolCurrency Cost Calculator
Input
Output
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Preview

How it works

Foreign amount is multiplied by mid-market and provider rates quoted as home currency per foreign unit. A flat fee, defaulting to 0, is added only to provider cost; spread percentage excludes it while effective rate includes it.

Formula
effective rate = (foreign amount × provider rate + flat fee) ÷ foreign amount
  • Margin amount compares complete provider cost with the mid-market conversion.
  • Quote direction is fixed, so inverse market quotes must be inverted before entry.

Worked example

1,000 dollars, mid rate 0.79
A provider offering 0.81 plus a 2.50 flat fee
Input
											Foreign amount: 1000
Mid market rate: 0.79
Provider rate: 0.81
Flat fee: 2.5
Output
												Home cost at mid rate: 790
Home cost at provider rate: 812.5
Exchange margin amount: 22.5
Exchange margin percent: 2.53
Effective rate: 0.81

When to use this

Travel card purchases, international bank transfers, and foreign-currency invoices compare a provider quote with the same-direction mid-market rate.

Edge cases

  • If provider rate is better than mid-market, exchange margin is negative rather than forced to a fee.
  • A flat fee changes effective rate and total margin amount but not the percentage spread embedded in provider rate.
  • Rates quoted in the inverse direction must be inverted before entry; the calculation always treats them as home currency per foreign unit.