How Currency Conversion Works
Converting between currencies is simple multiplication — but getting the rate direction backwards is a surprisingly common mistake.
convertedAmount = amount × rate, where rate is units of the target currency per 1 unit of the source currency. The inverse rate (1 ÷ rate) converts back the other way.
Direct rate vs inverse rate
If 1 USD = 0.92 EUR, that's the direct rate for converting USD → EUR. To convert EUR → USD, you need the inverse: 1 ÷ 0.92 ≈ 1.087 EUR → USD. Using the wrong direction gives a wildly incorrect result, not just a small error.
Why 'live' rates need a real source
Exchange rates move constantly, so any conversion is only as accurate as the rate it uses. A conversion done with a rate from a few hours ago can be meaningfully off during volatile periods — always use a rate from a source you trust and know the timestamp of.
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Frequently Asked Questions
What's the difference between mid-market rate and the rate I'll actually get?↓
The mid-market rate is the midpoint between buy and sell prices; banks and exchange services typically add a margin on top, so your effective rate is usually less favorable than the quoted mid-market rate.
Does this tool provide live exchange rates?↓
No — you enter the rate yourself from a source you trust, so the tool never shows a stale rate as if it were current.