Currency Impact on Investment Returns Calculator
See how exchange rate movements affect your real returns
Your real return in your home currency has two parts: how the asset performed, and how the currency moved between buying and selling. This tool splits the two and tells you, in plain words, whether the currency helped or hurt. It updates as you type.
Your investment
Free · No sign-up · Updates as you type
The currency you measure your wealth in.
The currency the investment is priced in (e.g. USD for a US stock).
€
How much you put in, in your home currency.
In the investment's own currency, before converting. Type 10 for a 10% gain, -10 for a 10% loss.
How did the currency move?
This calculator does not look up exchange rates. Type the two rates you actually got.
1 EUR = ? USD
1 EUR = ? USD
= USD strengthened by 4.8% against EUR
Your return in EUR, after the currency
+15.2%
€10,000 → €11,524
The currency worked in your favour.
In plain terms: your investment returned +10.0% in USD. USD strengthened by 4.8% against EUR, which added 5.2 points to your return. Together, in EUR you end with €11,524, a +15.2% return.
The numbers behind that
From the investment itself
+10.0% on your €10,000. If USD had not moved against EUR, you would have ended with €11,000.
+€1,000
From the currency
USD strengthened by 4.8% against EUR. The move applies to everything your investment was worth at the end, €11,000.
+€524
Your result in EUR
Your €10,000 became €11,524, a +15.2% return.
+€1,524
Where the answer flips
Your gain only turns into a loss if USD weakens by about 9.1% against EUR. Counting from the rate you bought at, the answer flips at an exchange rate of 1 EUR = 1.21 USD.
How the currency move changes your return
Nobody can predict exchange rates. This is what the same +10.0% would have come to in EUR under other currency moves. Your case is highlighted.
| Currency move (USD vs EUR) | Your return | You end with |
|---|---|---|
| -10.0% | -1.0% | €9,900 |
| -5.0% | +4.5% | €10,450 |
| 0.0% | +10.0% | €11,000 |
| +4.8% (yours) | +15.2% | €11,524 |
| +5.0% | +15.5% | €11,550 |
| +10.0% | +21.0% | €12,100 |
A plus sign means USD got stronger against EUR, which helps you. A minus sign means it got weaker, which costs you.
How Currency Movements Affect Your Investment Returns
When you invest in assets denominated in a foreign currency, your actual return depends on two things: how the asset performed AND how the exchange rate moved between the two currencies.
This is something many international investors overlook. You might see your US stock portfolio up 10% for the year, but when you convert back to your home currency, your real return could be significantly higher or lower depending on what happened to the exchange rate.
The key principle is simple:
- If your home currency weakened against the investment currency → your returns get a boost (you're converting back at a better rate)
- If your home currency strengthened against the investment currency → your returns get reduced (you're converting back at a worse rate)
For expats, digital nomads and anyone holding investments in more than one country, the currency effect can be larger than the investment return itself. In the second example further down this page, an 8% gain in euros becomes a 1.0% loss in New Zealand dollars.
The Formula Explained
Your total return in your home currency is calculated using this formula:
Total Return = (1 + Investment Return) × (1 + Currency Return) − 1
Where:
- Investment Return = the percentage gain or loss of the asset in its local currency
- Currency Return = the percentage change in the exchange rate over the holding period
With both rates written as 1 unit of your home currency = X units of the asset's currency, the currency return is (starting rate ÷ ending rate) - 1. Written the other way round, the division flips.
Why it's multiplicative, not additive:
A common mistake is to simply add the investment return and currency return together. For example, 10% investment return + 5% currency gain = 15%. But the actual combined return is slightly different: (1.10 × 1.05) − 1 = 15.5%. The difference grows with larger returns. This calculator handles the math correctly using the multiplicative formula.
Hedged vs Unhedged Investing
What is currency hedging?
Currency hedging is a strategy that aims to neutralise the impact of exchange rate movements on your foreign investments. When you hold a "hedged" investment (such as a hedged ETF), you receive approximately the same return as the underlying asset, regardless of what the exchange rate does.
When unhedged works in your favour:
If your home currency weakens, an unhedged foreign investment is worth more when you convert it back, on top of whatever the investment itself made.
When hedging protects you:
If your home currency strengthens unexpectedly, hedging protects you from losing returns on the conversion.
What this means in practice:
A single currency move can decide the result of a foreign investment, as the table in the calculator shows. Whether to hedge is a personal decision that depends on what hedging costs you, how long you plan to hold and how much swing you can live with. This page does not recommend either choice.
Real-World Examples for International Investors
Example 1: Australian investor in US stocks (AUD weakens)
An Australian investor puts A$50,000 into a US S&P 500 index fund when 1 AUD = 0.70 USD. After one year, the S&P 500 is up 12%, but the AUD has weakened to 0.64 USD. Their actual return in AUD is 22.5%, nearly double the index return, because the weaker AUD boosted the conversion back.
Example 2: NZ investor in European stocks (NZD strengthens)
A New Zealand investor puts NZ$30,000 into a European equity fund when 1 NZD = 0.55 EUR. The fund returns 8% in EUR, but the NZD strengthens to 0.60 EUR. Despite the positive investment return, the result in NZD is a loss of 1.0%: NZ$30,000 became NZ$29,700, because the currency moved against them.
Example 3: Expat holding home country assets
An expat from Italy living in Thailand holds €20,000 in Italian equities. If the EUR weakens against the THB while they're living in Thailand, their European investments become worth less in THB terms, even if the stock price hasn't changed. This calculator helps quantify exactly how much that currency shift costs (or benefits) them.
Frequently Asked Questions
No. This calculator focuses purely on the investment return and currency impact. Transaction costs, capital gains tax, and brokerage fees are not included. For a comprehensive view of your international investment performance, consider using a multi-currency portfolio tracker.
Use the rate at which you actually converted your money. If you transferred money through your bank or broker, use the rate they applied. If you haven't converted yet, use the current mid-market rate as an estimate.
Yes. If you bought Bitcoin in USD using AUD, you can enter the BTC return in USD and the AUD/USD exchange rates to see your real return in AUD.
This calculator is designed for a single investment event. For tracking multiple investments across different dates and exchange rates, a dedicated multi-currency portfolio tracker would be more suitable.
No. Hedging removes both the gain and the loss from currency moves. It also has its own cost, which depends largely on the difference in interest rates between the two currencies and can work for or against you. Whether it pays off depends on a currency move nobody can predict. This calculator shows the size of the currency effect on one investment; it does not tell you whether to hedge.
Position Sizing, Risk Management & Cross Border Investments
This calculator is built for investors, not for sizing leveraged forex trades. It takes one investment, the return it made in its own currency and the move in the exchange rate, and shows what that came to in your home currency. It does not model leverage, margin or stop losses, and it does not tell you how large a position to take. What it does show is how much of a result came from the currency, which is the first thing to know before deciding how much foreign currency risk you want to carry.
Cross border investments, owning assets in a different country from where you live, expose you to two layers of risk: the underlying asset's performance and the currency exchange rate between your investment and home currency. Over long time horizons, currency effects can either amplify or erode returns significantly. An investor in US stocks who earned 10% in USD terms but saw their home currency appreciate 5% against USD realised only 4.8% in local terms. This calculator models those exact cross border investment scenarios, helping you understand your true returns.
Conversion fees matter too. Banks and brokers charge for changing currency, either as a stated fee or inside the rate they give you, and this calculator does not add them for you. As an illustration, a 2% fee on a €100,000 conversion is €2,000, and you pay a fee again when you convert the money back. To count that cost here, type the rates you actually got, not the mid-market rates. Knowing how much of your wealth sits in each currency, which the currency exposure calculator on this site works out from the figures you enter, is the first step to seeing where conversions cost you most.
Also try our Graham Number Calculator for value investing analysis, or explore all our Financial Tools.
Track Your Multi-Currency Investments
With a free Worthmap account, you record your investments in the currency you hold them in and see your net worth in one base currency you pick, with a chart of how it changes over time, instead of redoing the conversions in a spreadsheet. The free plan is in beta.
Create free accountBuilt & maintained by Worthmap · Last updated October 6, 2026
Educational use only. This tool provides estimates for informational purposes and does not constitute financial, investment, tax, or legal advice. Results are based on inputs you provide and mathematical models, they do not guarantee future performance. Always consult a qualified financial adviser before making investment decisions.