Carry Trade Calculator

Written by Great Medico

Updated September 25, 2026 •2 min read

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A finance formula can look precise even when the assumptions behind it are doing most of the work. Carry Trade Calculator keeps those assumptions visible and turns the fields on this page into one focused result. On this page, it estimates the modeled profit or loss from an interest-rate carry trade after combining the borrowing/lending spread with the entered exchange-rate change.

What this calculator does

Carry Trade Calculator estimates the modeled profit or loss from an interest-rate carry trade after combining the borrowing/lending spread with the entered exchange-rate change. Its visible inputs are Initial exchange rate, Settle exchange rate, Days until trade settles, Lending rate, Borrowing rate, Amount invested. The article follows those fields and the calculation that is actually available on this page; it does not silently add live market feeds, tax tables, legal eligibility tests, or other variables that are not present in the tool.

How to use it

Enter Initial exchange rate, Settle exchange rate, Days until trade settles, Lending rate, Borrowing rate, Amount invested. Use the units and percentage scale shown beside each field, and keep values on the same time basis when the formula compares income, rates, prices, balances, or work hours. Pay special attention to quote direction: reversing a currency quote changes the mathematics even when the same two currencies are involved.

How the calculation works

The calculator first finds the exchange-rate change as (settlement rate − initial rate) ÷ initial rate. It then combines that currency move with the lending-minus-borrowing rate spread over days ÷ 360 and applies the modeled return to the amount invested.

Example

Using the page’s demonstration values (Initial exchange rate = 1.1; Settle exchange rate = 1.12; Days until trade settles = 90; Lending rate = 6) and leaving the remaining defaults unchanged, the calculator returns $100.3 for carry trade profit. Replace the sample inputs with values from the same period and definition before interpreting your own result.

How to interpret the result

Read the result as a model of the economic relationship represented by the inputs, not as a forecast of what an economy, market, currency, or policy authority will do next. Economic data are definition-sensitive: nominal versus real values, time periods, population bases, and price indexes must be aligned before comparing results.

Limitations and notes

Carry trades can lose money quickly when exchange rates move against the rate spread. Funding costs, bid/ask spreads, leverage, margin, taxes, rollover, and liquidity are not modeled. Simplified macroeconomic formulas hold other influences constant. Revisions to source data, measurement definitions, expectations, policy responses, market frictions, and nonlinear behavior can make real-world outcomes differ from the clean relationship shown here.