Real Return Calculator
Find out what your investment actually earned after accounting for inflation using the Fisher equation. Essential for retirees and long-term investors who need to know whether their portfolio is truly growing in purchasing power.
About this calculator
The nominal return on an investment is the headline percentage gain before adjusting for inflation. The real return strips out the effect of rising prices to reveal whether your purchasing power actually increased. The correct formula — known as the Fisher equation — is: Real Return (%) = ((1 + Nominal Return / 100) / (1 + Inflation Rate / 100) − 1) × 100. A common shortcut is simply to subtract the inflation rate from the nominal return, but this approximation overstates the real return slightly. The Fisher equation is exact. For example, if inflation is high, a seemingly healthy 8% nominal return may translate to a real return of only 4–5%, meaning your money's purchasing power grew far less than it appeared.
How to use
Suppose your portfolio returned 9% in a year when the inflation rate was 3.5%. Plug in: Real Return = ((1 + 9/100) / (1 + 3.5/100) − 1) × 100 = (1.09 / 1.035 − 1) × 100 = (1.05314 − 1) × 100 ≈ 5.31%. Your real, inflation-adjusted return was approximately 5.31%. Note that the simple subtraction method (9% − 3.5% = 5.5%) overstates it by about 0.19 percentage points — a small but meaningful difference over long periods.
Frequently asked questions
Why is the real return more important than the nominal return for long-term investors?
Nominal returns tell you how your portfolio grew in dollar terms, but dollars lose purchasing power over time due to inflation. A 7% nominal return during a 5% inflation environment leaves you with a real gain of less than 2%, meaning you can buy only slightly more with your money than you could before. Over a 20–30 year retirement horizon, a 1–2% difference in real return compounds into a massive difference in actual wealth. This is why long-term investors and retirees must focus on real, inflation-adjusted returns rather than headline figures.
What is the difference between the Fisher equation and the simple inflation adjustment method?
The simple method subtracts the inflation rate from the nominal return: Real Return ≈ Nominal Return − Inflation Rate. The Fisher equation is the precise version: Real Return = ((1 + Nominal) / (1 + Inflation) − 1) × 100. The simple method is a good approximation when both rates are small (under 5%), but the gap widens as rates increase. In high-inflation environments — such as the 1970s when U.S. inflation exceeded 10% — using the approximation can meaningfully misstate your true purchasing-power gain.
What real return should I expect from a diversified investment portfolio?
Historically, a diversified U.S. stock portfolio (like an S&P 500 index fund) has delivered a real return of approximately 6–7% per year over the long run, after accounting for inflation. Bonds have historically offered real returns of 1–3%. A balanced 60/40 stock-bond portfolio has typically yielded a real return of around 4–5% annually over multi-decade periods. These are historical averages and are not guaranteed — future returns may differ, especially in periods of structurally higher inflation or lower economic growth.