Real Interest Rate Calculator

Reviewed by the CalculatorHub team, edited by James Graham. Method from Federal Reserve. Last verified 2026-06-23.

The Real Interest Rate Calculator computes real interest rate from the relation real rate = ((1 plus nominal rate over 100) divided by (1 plus inflation rate over 100) minus 1) times 100. It takes 2 inputs (nominal interest rate in %, inflation rate in %) and returns the real interest rate. These calculators are for people working through everyday money questions: judging whether a price or an offer is worth taking, working out who owes what on a shared bill or cost, and comparing what one borrowing option costs against another, so the number feeds a concrete decision about spending, splitting or borrowing. Enter your values below and the result updates instantly, and you can share a permalink that pre-fills the exact calculation. Enter every amount in the same currency, and where a calculator uses a rate or a period, keep those on one consistent basis (monthly figures with monthly, annual with annual); be clear about whether each amount is before or after tax and fees, and round only the final figure rather than rounding at each step. For example, with nominal interest rate = 7 %, inflation rate = 3 %, the real interest rate works out to 3.883495, and the worked example further down the page shows every step so you can follow the arithmetic and reproduce it by hand. The method is the standard form documented by Federal Reserve, and the figure above each result carries the date it was last verified. The result is arithmetic on the amounts you type in, so what you actually pay or receive can differ once a seller's or lender's own rounding, fees, minimum charges and contract terms apply; use it as a working figure for your own planning and check it against the offer, statement or agreement in front of you.