What is the difference between covered and uncovered interest rate parity?

Covered IRP states that the forward exchange rate adjusts so that investors earn the same return in both currencies when exchange rate risk is hedged via a forward contract. Uncovered IRP states that the expected future spot rate adjusts to eliminate excess returns, relying on currency risk exposure rather than a hedge. Covered IRP holds well empirically; uncovered IRP is frequently violated.

How can I use IRP to detect arbitrage opportunities?

If the actual forward rate quoted in the market deviates from the CIP-implied forward rate, a covered interest arbitrage trade is theoretically possible: borrow in the low-rate currency, convert at spot, invest in the high-rate currency, and sell forward. In practice, transaction costs, credit risk, and capital constraints limit exploitable deviations.

Why does the higher interest rate currency typically trade at a forward discount?

A currency with higher interest rates offers higher nominal returns, attracting capital inflows that would create arbitrage if the forward rate did not offset the advantage. CIP requires the higher-rate currency's forward price to be lower than its spot price (a forward discount) by exactly the interest differential, eliminating the arbitrage.

Interest Rate Parity Calculator

Calculate the no-arbitrage forward exchange rate using Covered Interest Rate Parity (CIP), given the spot rate and domestic and foreign interest rates.

By AbraCalc Editorial Team · Reviewed by AbraCalc Methodology Review · Last reviewed: 2026-06-25

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How to use this tool

Enter spot exchange rate (domestic per foreign), domestic interest rate, foreign interest rate and time period in the fields above.
Results update instantly as you type — or click Calculate.
Read your forward exchange rate and the full breakdown beneath it.

⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.

Formula

Covered Interest Rate Parity (CIP):

F = S × (1 + r_d)^T / (1 + r_f)^T

Where F = forward rate, S = spot rate, r_d = domestic interest rate, r_f = foreign interest rate, T = time in years.

Forward Premium/Discount = (F − S) / S × 100

How it works

Covered Interest Rate Parity states that the difference between forward and spot exchange rates must equal the interest rate differential between two countries; otherwise risk-free arbitrage profits would be possible. A positive forward premium means the domestic currency is expected to depreciate relative to the foreign currency. The relationship underpins forward foreign exchange markets and currency hedging strategies.

Worked example

Spot 1.20, Domestic 5%, Foreign 3%, 1-year forward

Apply CIP formula: F = 1.20 × (1.05)^1 / (1.03)^1.
Compute: F = 1.20 × 1.05 / 1.03 = 1.20 × 1.019417... = 1.2233.
Forward premium = (1.2233 − 1.20) / 1.20 × 100 = 1.9417%.
This means the domestic currency is at a forward premium — it buys more foreign currency in the forward market.

Forward Rate: 1.2233 | Forward Premium: 1.9417%

Common mistakes to avoid

Confusing the direction of the quote: if the spot rate is expressed as USD per EUR, the forward rate formula uses domestic = USD and foreign = EUR. Reversing them produces a forward rate inverted from what you intend.
Applying the covered interest rate parity formula with annually compounded rates to short-dated (e.g., 3-month) forwards without adjusting T: for a 3-month forward, T = 0.25, not 1.
Conflating covered IRP (using forward contracts to lock in the rate) with uncovered IRP (which relies on expected future spot rates and holds only in expectation): the two have very different risk profiles and empirical support.

Key terms

What is Interest Rate Parity?: A no-arbitrage condition stating that the return from investing domestically must equal the hedged return from investing in a foreign currency after accounting for the forward exchange rate.
What is a forward exchange rate?: An agreed-upon price for exchanging currencies at a future date, set today in a forward contract to eliminate exchange-rate risk.
What is a forward premium?: When the forward rate is higher than the spot rate (in domestic/foreign terms), the domestic currency is said to trade at a forward premium, implying higher domestic interest rates.
What is the difference between covered and uncovered IRP?: Covered IRP involves a forward contract that locks in the exchange rate (eliminating risk). Uncovered IRP relies on expected future spot rates without hedging.

Frequently asked questions

What is the difference between covered and uncovered interest rate parity?: Covered IRP states that the forward exchange rate adjusts so that investors earn the same return in both currencies when exchange rate risk is hedged via a forward contract. Uncovered IRP states that the expected future spot rate adjusts to eliminate excess returns, relying on currency risk exposure rather than a hedge. Covered IRP holds well empirically; uncovered IRP is frequently violated.
How can I use IRP to detect arbitrage opportunities?: If the actual forward rate quoted in the market deviates from the CIP-implied forward rate, a covered interest arbitrage trade is theoretically possible: borrow in the low-rate currency, convert at spot, invest in the high-rate currency, and sell forward. In practice, transaction costs, credit risk, and capital constraints limit exploitable deviations.
Why does the higher interest rate currency typically trade at a forward discount?: A currency with higher interest rates offers higher nominal returns, attracting capital inflows that would create arbitrage if the forward rate did not offset the advantage. CIP requires the higher-rate currency's forward price to be lower than its spot price (a forward discount) by exactly the interest differential, eliminating the arbitrage.