Why not just subtract?
The exact formula divides: real return = (1 + return) ÷ (1 + inflation) − 1. Subtracting gives a close number when rates are low, but it drifts when they are high.
Example
An investment that returned 5% in a year with 3% inflation had a real return of about 1.94%.
Frequently asked questions
Where do I find inflation?
In the US, the Bureau of Labor Statistics publishes the Consumer Price Index (CPI) every month.
See also
Results are estimates for information only and are not financial, legal or medical advice. Rates, taxes and fees vary — confirm with a professional or your lender.