Nominal to Real Rate Calculator
Find the real interest rate after inflation.
Results update as you type.
How it works
The real interest rate tells you your true return after inflation, and this calculator computes it from a nominal rate and inflation. You enter the nominal rate, the stated interest or return rate, and the inflation rate, and it returns the exact real rate using the Fisher equation and a simpler approximation. The nominal rate is what a bank quotes or an investment reports, but it does not account for the erosion of purchasing power by inflation. The real rate strips that out, showing how much your money actually grows in terms of what it can buy. The exact Fisher formula divides one plus the nominal rate by one plus the inflation rate and subtracts one, while the common approximation just subtracts inflation from the nominal rate. The approximation is close when rates are low, for example a 7 percent nominal rate minus 3 percent inflation gives about 4 percent, while the exact formula gives about 3.88 percent, but the gap widens at higher rates, so the exact version is better for high-inflation environments. This distinction matters for saving and investing: a savings account paying 2 percent while inflation runs 4 percent has a negative real rate, meaning your money loses purchasing power despite the nominal gain. Investors and economists use the real rate to judge whether returns genuinely build wealth. Enter the nominal rate and inflation rate to find the real rate of return.
Real rate = (1 + nominal) / (1 + inflation) − 1
The Fisher equation gives the exact real interest rate as one plus the nominal rate divided by one plus the inflation rate, minus one. A common approximation simply subtracts inflation from the nominal rate, which is close when both rates are small but less accurate at higher rates.
Source:Fisher equation
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter nominal rate and inflation rate.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Real rate (exact) updates instantly as you type — no button to press.
Frequently asked questions
What is the difference between nominal and real interest rates?
The nominal rate is the stated rate, what a bank quotes or an investment reports, without adjusting for inflation. The real rate subtracts the effect of inflation, showing your true growth in purchasing power. If inflation exceeds the nominal rate, the real rate is negative, meaning your money buys less over time despite the nominal gain.
What is the Fisher equation?
The Fisher equation relates nominal and real rates: one plus the real rate equals one plus the nominal rate divided by one plus the inflation rate. Rearranged, the real rate is that quotient minus one. It gives the exact real interest rate, more precise than simply subtracting inflation from the nominal rate, especially when rates are high.
When can I just subtract inflation from the nominal rate?
The approximation, real rate equals nominal minus inflation, is close when both rates are low, within a few percent, because the compounding effect the exact formula captures is small. At higher inflation or interest rates the approximation drifts from the exact value, so use the Fisher equation for accuracy in high-rate environments.
Why does the real rate matter for savings?
Your savings only build real wealth if their return beats inflation. A savings account paying 2 percent while inflation is 4 percent has a real rate of about negative 2 percent, so your money loses purchasing power even as the balance grows. Looking at the real rate, not just the nominal rate, reveals whether you are actually getting ahead.
Can the real rate be negative?
Yes. When inflation is higher than the nominal interest or return rate, the real rate is negative, meaning the purchasing power of your money declines over time despite earning nominal interest. Negative real rates are common for low-yield savings during periods of higher inflation, which is why comparing returns to inflation is essential.