Real Interest Rate
Quick Definition
The interest rate adjusted for inflation, representing the true cost of borrowing or the true return on savings in terms of purchasing power.
Key Takeaways
- Nominal interest rate minus inflation rate
- Represents the true change in purchasing power for savers and borrowers
- Can be negative when inflation exceeds nominal rates
- The Fisher equation: real rate ≈ nominal rate - inflation rate
- Better measure of monetary policy stance than nominal rates alone
What Is Real Interest Rate?
The real interest rate is the nominal interest rate minus the inflation rate, representing the actual increase in purchasing power that a lender receives or the true cost of borrowing for a borrower. If a savings account pays 5% nominal interest but inflation is 3%, the real interest rate is approximately 2%—the saver's purchasing power grows by only 2%. Real rates can be negative when inflation exceeds nominal rates, meaning savers lose purchasing power despite earning positive nominal returns. The Fisher equation formalizes this: real rate ≈ nominal rate - inflation rate (or more precisely: 1 + real = (1 + nominal) / (1 + inflation)). Real interest rates drive economic decisions: investment projects are evaluated against real borrowing costs, not nominal rates. The Federal Reserve's policy stance is best measured by comparing the federal funds rate to inflation—a positive real rate is restrictive; a negative real rate is stimulative.
Real Interest Rate Example
- 1With the federal funds rate at 5.25% and core inflation at 3.5%, the real interest rate was approximately 1.75%—a meaningfully restrictive policy stance.
- 2During 2021-2022, real interest rates were deeply negative (-4% to -6%), effectively paying borrowers to take on debt and discouraging savings.
- 3TIPS (Treasury Inflation-Protected Securities) directly reveal the real interest rate because their yields are quoted after inflation adjustment.
Related Terms
Federal Funds Rate
The interest rate at which banks lend reserve balances to each other overnight, set as a target range by the Federal Reserve.
Inflation
The rate at which the general level of prices for goods and services rises over time, reducing the purchasing power of money.
Neutral Interest Rate (r*)
The theoretical interest rate that neither stimulates nor restricts economic growth, keeping the economy at full employment with stable inflation.
Real vs. Nominal Values
Nominal values are measured in current prices without inflation adjustment, while real values are adjusted for inflation to reflect actual purchasing power.
Monetary Policy
Actions by a central bank to manage the money supply and interest rates to achieve macroeconomic objectives like stable prices and full employment.
Expand Your Financial Vocabulary
Explore 130+ financial terms with definitions, examples, and formulas
Browse Macroeconomics Terms