Forward Exchange Rate Calculator
Estimate the theoretical forward FX rate using covered interest parity. Enter rates as annual percentages.
What is a forward exchange rate?
A forward exchange rate is the agreed exchange rate today for a currency transaction that will settle in the future. Businesses, investors, and treasury teams use forwards to reduce uncertainty from currency moves. Instead of guessing where spot rates might go, they lock in a rate based on current spot and interest-rate differentials.
This calculator estimates the theoretical fair forward rate from covered interest parity (CIP). In efficient markets, this parity relationship helps prevent arbitrage between cash, borrowing, lending, and FX conversion.
Formula used by this calculator
1) Money-market (simple interest)
F = S × (1 + rd × t) / (1 + rf × t)
- F = forward exchange rate
- S = current spot exchange rate
- rd = domestic annual interest rate (decimal)
- rf = foreign annual interest rate (decimal)
- t = year fraction to maturity
2) Annual compounding (discrete)
F = S × (1 + rd)t / (1 + rf)t
3) Continuous compounding
F = S × e(rd − rf)t
All three methods are useful depending on the convention used in your model, institution, or market documentation.
How to use the calculator
- Enter the current spot rate for your currency pair.
- Enter domestic and foreign annualized rates (in percent, not decimals).
- Set maturity (days, months, or years).
- Select the compounding method and click Calculate Forward Rate.
The tool returns the forward rate, forward points (difference versus spot), and the implied premium/discount percentage.
Worked example
Suppose:
- Spot EUR/USD = 1.1000
- Domestic rate = 5.00%
- Foreign rate = 3.00%
- Tenor = 6 months (0.5 years)
Using the simple money-market formula:
F = 1.1000 × (1 + 0.05×0.5)/(1 + 0.03×0.5) = 1.1108 (approx.)
The forward is above spot, so the pair trades at a forward premium under these assumptions.
How to interpret forward points and premium/discount
- Forward points: typically shown as
F − Sin pips (×10,000 for most major pairs). - Premium: if forward rate is above spot.
- Discount: if forward rate is below spot.
In basic CIP logic, if domestic interest rates are higher than foreign rates, the forward rate tends to be higher than spot (all else equal).
Common mistakes to avoid
- Entering rates as decimals (0.05) instead of percentages (5.00).
- Using the wrong domestic/foreign side for a currency quote.
- Ignoring day-count conventions for short-dated forwards.
- Treating the forward as a market forecast (it is primarily a parity-implied value).
Frequently asked questions
Is the forward rate a prediction of future spot?
Not necessarily. The no-arbitrage forward is driven by spot and rate differentials. Future spot can end up higher or lower.
Can I use negative interest rates?
Yes. The calculator supports negative rates, but values that break the selected formula domain (for example, compounding base less than or equal to zero) will trigger an error.
Which method should I choose?
Use the convention your desk, textbook, or pricing policy requires. Money-market simple interest is common for practical short-dated forward calculations.
Final thought
A forward exchange rate calculator is a practical way to connect FX pricing with interest-rate fundamentals. Whether you hedge receivables, compare cross-border returns, or study international finance, understanding this relationship gives you a clearer framework for decision-making.