Headlines say “the dollar fell 6%” or “the yen hit a new low”, but a currency’s move always depends on which way you look at the pair. When one currency weakens against another, the other strengthens — by a slightly different percentage. This calculator gives both numbers from two exchange rates, so you can describe the change correctly for either side.
How to use the currency appreciation calculator
- Enter the base currency code (the currency being priced, such as USD) and the quote currency code (such as EUR).
- Enter the earlier exchange rate and the later exchange rate, both as units of the quote currency per 1 unit of the base currency.
- Optionally enter an amount of the base currency to see what it was worth then and now.
- Read the base currency’s change on the tape and the quote currency’s change below it.
Appreciation and depreciation formulas
A positive result means the currency appreciated (it buys more of the other currency); a negative result means it depreciated.
Worked example
One US dollar bought 0.92 euros at the start of the year and 0.86 euros at the end.
Dollar change = 0.86 ÷ 0.92 − 1 = −6.52% — the dollar depreciated against the euro
Euro change = 0.92 ÷ 0.86 − 1 = +6.98% — the euro appreciated against the dollar
$1,000 was worth €920.00 and is now worth €860.00, a loss of €60.00 in euro terms
The two percentages differ because a 6.52% fall from 0.92 and a 6.98% rise from 0.86 describe the same move from opposite starting points.
Same move, two percentages
| Base currency change | Quote currency change |
|---|---|
| −2% | +2.04% |
| −5% | +5.26% |
| −10% | +11.11% |
| −20% | +25% |
| −50% | +100% |
| +10% | −9.09% |
The gap is small for small moves and grows quickly for large ones. A currency that loses half its value means the other currency has doubled against it.
Why exchange-rate changes matter
Travel and purchases abroad
If your home currency depreciates 7% before a trip, hotels and meals priced in the local currency cost about 7.5% more in your money.
Investments in foreign assets
A US investor in European stocks earns the stocks’ return in euros plus the euro’s change against the dollar. A 5% stock gain combined with the euro appreciating 6.98% gives roughly 1.05 × 1.0698 − 1 = 12.3% in dollars.
Business margins
Importers paying suppliers in a currency that appreciates see costs rise without any change in the supplier’s price. Exporters benefit from the same move.
Rate quoting conventions
Markets quote some pairs with the dollar as the base (USD/JPY, USD/CAD) and others with the dollar as the quote (EUR/USD, GBP/USD, AUD/USD). Always check which currency the “1” refers to before calculating.
For today’s rates, use the currency converter. To compare a currency’s change with domestic price inflation, see the inflation calculator.
Results are estimates for education and planning, not investment or trading advice. Exchange rates change constantly.
Frequently asked questions
How do I calculate currency appreciation?
Write the rate as units of the quote currency per one unit of the base currency. The base currency's change is new rate ÷ old rate − 1. If one US dollar went from 0.92 to 0.86 euros, the dollar changed by 0.86 ÷ 0.92 − 1 = −6.52%, a depreciation.
Why isn't the other currency's change the same percentage?
Each change is measured from a different starting value. The quote currency's change is old rate ÷ new rate − 1, so in the example the euro appreciated 0.92 ÷ 0.86 − 1 = +6.98% against the dollar, not 6.52%.
How do I know which currency is the base?
The base currency is the one with 1 unit in the quote. EUR/USD = 1.08 means 1 euro costs 1.08 dollars, so the euro is the base. A quote of 0.92 EUR per USD has the dollar as the base.
Is depreciation the same as devaluation?
Both mean a currency loses value against others. Depreciation usually refers to market-driven changes in a floating exchange rate, while devaluation refers to a deliberate cut in an official, fixed or pegged rate by a government or central bank.