Personal economy
Real Interest Rate Calculator
Compare nominal interest with inflation using approximate and exact Fisher calculations.
Runs locally
Inputs and results stay in this browser. Currency symbols are illustrative; use any consistent currency.
Exact real interest rate2.91%
Fisher approximation3%
Formula
Exact real rate = (1 + nominal rate) ÷ (1 + inflation rate) − 1
How to interpret the result
The subtraction shortcut is useful for small rates. The Fisher calculation is more accurate because it accounts for compounding.
Assumptions and limitations
This calculator is an educational estimate, not financial, investment, tax or policy advice. Use consistent units and verify material decisions against primary data and professional guidance.
Last reviewed 2026-07-14. Calculations tested 2026-07-14.