Finance

Instant, private, and free

Interest Rate Parity Calculator.

Estimate a forward exchange rate from spot and two interest rates.

On-device calculationNo signup

Set your values

Results update as you type.

02 / ANSWER

Spot exchange rate

Domestic interest rate

Foreign interest rate

Horizon

Implied forward rate

0.00

FAQs

How does the interest rate parity calculator work?

Enter the requested values to see a deterministic result. Assumptions are explicit and no live market or tax data is fetched.

Use Cases

Identify arbitrage opportunities

Compare the calculated forward rate with the market forward rate to spot potential risk-free profit from interest rate differentials.

Example: If the calculated forward rate is 1.20 and the market rate is 1.25, you might consider a covered interest arbitrage.

Hedge currency risk

Use the parity-based forward rate to set fair forward contracts for hedging future foreign currency cash flows.

Example: A company expecting to receive EUR in 6 months can use the calculator to determine a fair forward rate.

Frequently Asked Questions

What is interest rate parity?: Interest rate parity is a theory in finance that states the difference in interest rates between two countries is equal to the difference between the forward exchange rate and the spot exchange rate. This ensures that investors cannot earn risk-free profits through arbitrage in the foreign exchange market.
How do I use this calculator?: Enter the spot exchange rate, the domestic and foreign interest rates, and the time period. The calculator will compute the forward exchange rate implied by interest rate parity, helping you see if the actual forward rate aligns with the theory.
What does the result tell me?: The result shows the forward exchange rate that should exist according to interest rate parity. If the actual forward rate differs, it may indicate an arbitrage opportunity, though transaction costs and market frictions can affect real-world outcomes.

Tips & Common Mistakes

Tips

Ensure you use consistent time periods (e.g., annual rates for a 1-year forward, or adjust for shorter periods).
Use the same currency units for spot and forward rates to avoid confusion.
Remember that interest rates should be expressed as decimals (e.g., 5% as 0.05) or percentages consistently.
Check if the calculator uses continuous compounding or simple interest; adjust your inputs accordingly.

Common Mistakes to Avoid

Mixing up domestic and foreign interest rates – always label them correctly.
Forgetting to convert interest rates to the same time period as the forward contract.
Assuming the result is a prediction of future spot rates; it is only a theoretical equilibrium rate.

Last updated: August 13, 2026

Use Cases

Identify arbitrage opportunities

Compare the calculated forward rate with the market forward rate to spot potential risk-free profit from interest rate differentials.

Example: If the calculated forward rate is 1.20 and the market rate is 1.25, you might consider a covered interest arbitrage.

Hedge currency risk

Use the parity-based forward rate to set fair forward contracts for hedging future foreign currency cash flows.

Example: A company expecting to receive EUR in 6 months can use the calculator to determine a fair forward rate.

Frequently Asked Questions

What is interest rate parity?

Interest rate parity is a theory in finance that states the difference in interest rates between two countries is equal to the difference between the forward exchange rate and the spot exchange rate. This ensures that investors cannot earn risk-free profits through arbitrage in the foreign exchange market.

How do I use this calculator?

Enter the spot exchange rate, the domestic and foreign interest rates, and the time period. The calculator will compute the forward exchange rate implied by interest rate parity, helping you see if the actual forward rate aligns with the theory.

What does the result tell me?

The result shows the forward exchange rate that should exist according to interest rate parity. If the actual forward rate differs, it may indicate an arbitrage opportunity, though transaction costs and market frictions can affect real-world outcomes.

Tips & Common Mistakes

Tips

Ensure you use consistent time periods (e.g., annual rates for a 1-year forward, or adjust for shorter periods).
Use the same currency units for spot and forward rates to avoid confusion.
Remember that interest rates should be expressed as decimals (e.g., 5% as 0.05) or percentages consistently.
Check if the calculator uses continuous compounding or simple interest; adjust your inputs accordingly.

Common Mistakes to Avoid

Mixing up domestic and foreign interest rates – always label them correctly.
Forgetting to convert interest rates to the same time period as the forward contract.
Assuming the result is a prediction of future spot rates; it is only a theoretical equilibrium rate.

Finance

Instant, private, and free

Interest Rate Parity Calculator.

Estimate a forward exchange rate from spot and two interest rates.

On-device calculationNo signup

Set your values

Results update as you type.

02 / ANSWER

Spot exchange rate

Domestic interest rate

Foreign interest rate

Horizon

Implied forward rate

0.00

FAQs

How does the interest rate parity calculator work?

Enter the requested values to see a deterministic result. Assumptions are explicit and no live market or tax data is fetched.

Related Calculators

Effective Duration CalculatorCalculate effective duration from explicit user inputs with transparent assumptions and instant, debounced results.Effective Interest Rate CalculatorCalculate effective interest rate from explicit user inputs with transparent assumptions and instant, debounced results.EMV CalculatorCalculate emv from explicit user inputs with transparent assumptions and instant, debounced results.Ending Inventory CalculatorCalculate ending inventory from explicit user inputs with transparent assumptions and instant, debounced results.Enterprise Value CalculatorCalculate enterprise value from explicit user inputs with transparent assumptions and instant, debounced results.EOQ CalculatorCalculate eoq from explicit user inputs with transparent assumptions and instant, debounced results.

Use Cases

Identify arbitrage opportunities

Compare the calculated forward rate with the market forward rate to spot potential risk-free profit from interest rate differentials.

Example: If the calculated forward rate is 1.20 and the market rate is 1.25, you might consider a covered interest arbitrage.

Hedge currency risk

Use the parity-based forward rate to set fair forward contracts for hedging future foreign currency cash flows.

Example: A company expecting to receive EUR in 6 months can use the calculator to determine a fair forward rate.

Frequently Asked Questions

What is interest rate parity?: Interest rate parity is a theory in finance that states the difference in interest rates between two countries is equal to the difference between the forward exchange rate and the spot exchange rate. This ensures that investors cannot earn risk-free profits through arbitrage in the foreign exchange market.
How do I use this calculator?: Enter the spot exchange rate, the domestic and foreign interest rates, and the time period. The calculator will compute the forward exchange rate implied by interest rate parity, helping you see if the actual forward rate aligns with the theory.
What does the result tell me?: The result shows the forward exchange rate that should exist according to interest rate parity. If the actual forward rate differs, it may indicate an arbitrage opportunity, though transaction costs and market frictions can affect real-world outcomes.

Tips & Common Mistakes

Tips

Ensure you use consistent time periods (e.g., annual rates for a 1-year forward, or adjust for shorter periods).
Use the same currency units for spot and forward rates to avoid confusion.
Remember that interest rates should be expressed as decimals (e.g., 5% as 0.05) or percentages consistently.
Check if the calculator uses continuous compounding or simple interest; adjust your inputs accordingly.

Common Mistakes to Avoid

Mixing up domestic and foreign interest rates – always label them correctly.
Forgetting to convert interest rates to the same time period as the forward contract.
Assuming the result is a prediction of future spot rates; it is only a theoretical equilibrium rate.

Last updated: August 13, 2026