Currency Forward Calculator

The currency forward calculator estimates the future exchange rate implied by a spot quote and two short-term interest rates. It is designed for the common treasury question: if a currency pair trades at a given spot price today, and the two currencies earn different money-market rates until settlement, what forward price would make the interest-adjusted exchange economically balanced? The result includes the forward price, forward points, each period interest rate, and the forward premium or discount from spot.

This page is informational, not investment advice; FX is high-risk. A theoretical forward rate is a pricing benchmark, not a guarantee of execution. Actual dealer quotes can reflect bid-ask spreads, credit charges, collateral terms, settlement calendars, broken-date adjustments, liquidity, and the size of the transaction. Use the calculator to understand the mechanics before comparing bank or broker quotes.

Inputs and quote convention

The spot price should be entered in the same direction as the forward contract: price currency per one unit of base currency. If the pair is quoted as GBP per MYR, the output is also GBP per MYR. If you invert the spot quote, you must invert how you read the result. The contract length is entered in calendar days, and this calculator converts the annual rates to period rates using a 360-day money-market year.

The price currency annual rate is the annualized interest rate for the currency that appears in the price of the quote. The base currency annual rate is the annualized rate for the currency being priced. The calculator accepts percentage inputs, so enter 0.8 for 0.8 percent, not 0.008. It rejects negative spot prices, negative terms, invalid numeric, and the impossible case where the denominator would equal zero.

Formula

First, each annual percentage rate is converted to a decimal period rate:

$\text{price period rate} = \frac{\text{price annual rate}}{100} \times \frac{\text{days}}{360}$

$\text{base period rate} = \frac{\text{base annual rate}}{100} \times \frac{\text{days}}{360}$

Then the calculator applies the interest-rate parity forward-price relationship:

$\text{forward price} = \text{spot price} \times \frac{1 + \text{price period rate}}{1 + \text{base period rate}}$

Forward points and the displayed premium or discount are:

$\text{forward points} = \text{forward price} - \text{spot price}$

$\text{premium or discount} = \frac{\text{forward points}}{\text{spot price}} \times 100$

Worked example using the default inputs

The default form values are a spot price of 0.1735, a 90-day term, a price currency annual rate of 0.8 percent, and a base currency annual rate of 3.2 percent. The calculator first scales the annual rates to the contract period: 0.8 divided by 100, multiplied by 90 divided by 360, equals 0.002. The base period rate is 3.2 divided by 100, multiplied by 90 divided by 360, which equals 0.008.

The forward price is therefore 0.1735 multiplied by 1.002 divided by 1.008. That equals 0.1724672619, displayed as 0.172467. The forward points are 0.1724672619 minus 0.1735, or negative 0.0010327381, displayed as -0.001033. The premium or discount is the points divided by spot, multiplied by 100, which equals about negative 0.595238 percent. The output is below spot because the base currency rate is higher than the price currency rate for the same term.

How currency forwards are used

Businesses use forwards to lock a rate for future receivables, payables, loan repayments, dividends, and acquisitions. An importer with a known foreign-currency bill may prefer certainty over waiting for the spot market. An exporter expecting foreign-currency revenue may hedge so that local-currency cash flow is known for budgeting. Investors and funds use forwards to hedge portfolio exposures or to separate currency risk from asset selection.

The forward price is closely related to other international-finance calculators. The interest rate parity calculator uses a similar spot-and-rate relationship with a 365-day convention and a covered or uncovered label. The forward rate calculator applies the same no-arbitrage idea to interest-rate maturities rather than currency pairs. If you only need today’s indirect spot conversion, use the cross exchange rate calculator.

Risks and practical tips

Forward contracts reduce one kind of uncertainty but introduce others. If the future spot rate moves favorably, a locked forward can be worse than doing nothing. If the contract is closed early, marked to market, or collateralized, cash-flow timing can matter as much as the final settlement. Counterparty risk also matters for over-the-counter forwards, especially for long terms or large notionals.

For cleaner analysis, keep the quote direction visible in your worksheet, use the same day-count convention as the quote you are checking, and separate the model price from the all-in dealing rate. Compare the forward points with the interest-rate gap: a small interest differential over a short term should usually create small points, while a wide differential over a long term should be more visible. Never treat the theoretical forward as a forecast of where spot must trade at maturity.

Sources

• Federal Reserve, Quantities and Covered-Interest Parity — Finance and Economics Discussion Series 2024-061; accessed 2026-07-09; Supports covered-interest-parity framing. This scenario uses entered simple annual rates and a 360-day basis; it is not a live executable forward quote.
• Calculation scope: The equations and assumptions described above are applied only to values entered in the form. No live rates, prices, tax rules, lender terms, or accounting classifications are fetched. Results are user scenarios, not quotes or prescribed classifications.