Money ManagementETF vs Mutual Fund: Which Is Better for Beginners?
ETF vs Mutual Fund: Which Is Better for Beginners? Explore costs, tax implications, and trading flexibility for informed investment decisions.
MAJun 11, 2026Read More →
Real Interest Rate Calculator
See what your savings truly earn after inflation. Enter a nominal rate, expected inflation, an amount and a horizon, then press Calculate to find the real rate and how much buying power slips away.
Written by TopicDrill Editorial Team·Updated June 2026
Nominal value vs real purchasing power
Nominal Real
Advertisement
How the real interest rate calculator works
Interest rates are usually quoted in nominal terms, the plain number a bank or bond advertises. But what you really care about is buying power. This tool feeds your nominal rate and your inflation estimate into the Fisher equation to return the rate that matters: what your money earns after rising prices are accounted for.
The chart traces two lines. The dashed line is the nominal balance climbing at the stated rate, while the shaded area is the same balance restated in today's dollars. The widening gap between them is purchasing power quietly draining away.
A quick example
Suppose a deposit pays six percent a year while inflation runs three percent. The exact real rate is not three percent but about 2.91 percent, because inflation also nibbles at the interest itself. Over twenty years a 10,000 dollar deposit grows to roughly 32,071 dollars on paper, yet in today's money it is worth only about 17,756 dollars, a real gain far smaller than the headline balance suggests.
Things to keep in mind
Inflation is an estimate, so the real rate is a forecast rather than a guarantee. For official inflation figures from a neutral source, see the U.S. Bureau of Labor Statistics CPI page. To project the nominal growth side on its own, try our future value calculator.
Frequently asked questions
What is the real interest rate?
The real interest rate is the return you earn after stripping out inflation. It measures the gain in actual buying power rather than the headline number on a statement. If a bond pays five percent while prices rise three percent, your money only buys about two percent more than before.
What is the Fisher equation?
The Fisher equation links the three rates exactly: one plus the real rate equals one plus the nominal rate divided by one plus the inflation rate. This calculator uses that exact form and also shows the rough shortcut of nominal minus inflation so you can compare the two.
Why is nominal minus inflation only an approximation?
Simply subtracting inflation from the nominal rate ignores that inflation also erodes the interest you earn, not just the principal. The gap between the shortcut and the exact Fisher figure is tiny at low rates but grows noticeably when both rates are high.
Can the real interest rate be negative?
Yes. When inflation runs higher than the rate your savings earn, the real rate turns negative and your money loses buying power even though the balance keeps rising. This is common with low-yield savings accounts during periods of elevated inflation.
Related guides
View all →
Business FinanceHow Much Will $1,000 Invested Today Be Worth in 10 Years?
Invest $1,000 today and the answer to "what's it worth in 10 years?" ranges from about $1,040 in a basic savings account to roughly $2,594 at the stock market's long-run average. Here's the math behind every scenario — plus how inflation, fees and taxes change the real number.
MAJun 9, 2026Read More →
Business FinanceHow Much Do You Need to Retire Comfortably? (2026 Guide)
There's no single magic number for retirement — but there are proven formulas that get you close. Using the 4% rule, most people need roughly 25 times their annual spending invested. Here's how to find your personal target, factoring in Social Security, healthcare, inflation and lifestyle.
MAJun 9, 2026Read More →
Advertisement