Currency Calculator
Convert between 30 currencies using Frankfurter's daily reference exchange rate, with an optional illustrative spread to estimate a markup or cost against the reference rate.
How It's Calculated
Formula
\text{Converted} = \text{Amount} \times \text{Rate}\\ \text{Effective Rate} = \text{Rate} \times \left(1 - \frac{\text{Spread\%}}{100}\right)This calculator converts an amount between two currencies using Frankfurter's daily reference exchange rate — a rate published once per business day from central-bank and reference-market sources, not a live, tick-by-tick trading quote and not a bid/ask price. The "Reference Converted Amount" is simply your amount multiplied by that reference rate. The "Illustrative spread" is an optional percentage YOU enter to estimate the effect of a markup or cost — your bank, card network, or currency exchange may charge above the reference rate, and this field lets you model that; it is not the provider's own spread and does not reflect any real-time bid/ask. The "Spread-Adjusted Amount" applies that illustrative spread to the reference rate before converting. At a 0% spread, the spread-adjusted amount always equals the reference converted amount exactly. The rate date shown is the provider's own reference-rate date — on weekends and market holidays, this may be the most recent prior business day's rate, which is expected and not an error. Your actual bank, card, or exchange rate and any fees they charge will very likely differ from this reference rate.
Worked Examples
Convert $100 USD to EUR at a 0.8726 reference rate, no spread
- Reference Converted Amount = 100 × 0.8726 = €87.26
- Effective Rate = 0.8726 × (1 − 0/100) = 0.8726 (unchanged — 0% spread)
- Spread-Adjusted Amount = 100 × 0.8726 = €87.26 — identical to the reference conversion, as expected at 0% spread
Convert $100 USD to EUR at a 0.8726 reference rate, with a 1% illustrative spread
- Reference Converted Amount = 100 × 0.8726 = €87.26
- Effective Rate = 0.8726 × (1 − 1/100) = 0.8726 × 0.99 = 0.863874
- Spread-Adjusted Amount = 100 × 0.863874 = €86.3874, displayed as €86.39
Frequently Asked Questions
Is this a live, real-time exchange rate?
No. This calculator uses Frankfurter's daily reference rate, updated once per business day from central-bank and reference-market sources — not a live, tick-by-tick trading quote and not a bid/ask price you could execute a trade at.
What does the illustrative spread mean — is it my bank's real spread?
No. The illustrative spread is a percentage you enter yourself to estimate how a markup or cost (from a bank, card network, or exchange) might affect your converted amount against the reference rate. It is not a live bid/ask spread and does not come from any provider — it's a what-if value you control.
Why does the rate date not always match today's date?
The reference rate is only published on business days. On weekends and market holidays, the most recently published rate is shown along with its actual date — this is expected provider behavior, not a calculator error.
Which currencies are supported?
The 30 currencies published by Frankfurter's reference-rate feed, including USD, EUR, GBP, JPY, CAD, and more — selectable from a fixed list, not free text.
Will this match what my bank, card, or currency exchange actually charges me?
Not necessarily. Banks, card networks, and currency exchanges typically apply their own markup and fees on top of a reference rate like this one — this calculator's spread-adjusted amount is only as accurate as the illustrative spread percentage you enter.
What happens if I select the same currency for both From and To?
The reference rate is fixed at 1 and no external data is requested — you'll see "Same-currency conversion — rate fixed at 1" instead of a fabricated rate date, since no real provider lookup happened.