What Is an Interest Rate?

Interest rates are among the most powerful forces in the global economy. When the Federal Reserve raises or cuts rates, it affects your mortgage, your savings account, the stock market, and the value of every dollar in your wallet. Yet most Americans have only a vague sense of how rates actually work.

What Is an Interest Rate?

An interest rate is the cost of borrowing money, expressed as an annual percentage. When you take out a loan, the interest rate determines how much extra you pay back on top of the amount you borrowed. When you save money, the interest rate determines how much the bank pays you for using your funds.

How the Federal Reserve Controls Interest Rates

The Federal Reserve sets the federal funds rate — the rate at which banks lend money to each other overnight. This benchmark rate influences all other interest rates in the economy, from mortgages to credit cards to savings accounts.

The Fed's rate-setting body, the FOMC (Federal Open Market Committee), meets eight times per year. When they raise rates, borrowing becomes more expensive and saving becomes more rewarding. When they cut rates, borrowing becomes cheaper and spending is encouraged.

Types of Interest Rates You Need to Know

Federal Funds Rate

The overnight rate between banks — the Fed's primary policy tool. All other rates are influenced by this benchmark. When it rises, borrowing costs rise across the economy within weeks.

Prime Rate

The prime rate is what banks charge their best commercial customers. It runs about 3 percentage points above the federal funds rate. Many consumer loans — HELOCs, some credit cards — are tied directly to the prime rate.

Mortgage Rate

Mortgage rates are closely tied to the 10-year Treasury yield rather than the federal funds rate directly. Fixed-rate mortgages lock in your rate for 15-30 years; adjustable-rate mortgages (ARMs) can change periodically, creating risk when rates rise.

Discount Rate

The discount rate is what the Federal Reserve charges banks that borrow directly from the Fed's emergency "discount window." It signals the Fed's role as a lender of last resort during financial crises.

Variable vs Fixed Rates

Fixed rates remain constant for the loan's life — predictable but often start higher. Variable rates adjust with market conditions — start lower but carry the risk of rising. During the 2022-2023 rate hikes, homeowners with adjustable-rate mortgages saw monthly payments jump by hundreds of dollars.

How Interest Rates Affect Your Daily Life

Why the Fed Raises and Cuts Rates

The Federal Reserve has a dual mandate: maximum employment and stable prices (targeting 2% inflation). These goals sometimes conflict, requiring the Fed to make difficult tradeoffs.

• When inflation is too high: The Fed raises rates → borrowing becomes more expensive → people and businesses spend less → demand falls → prices stop rising
• When unemployment is too high: The Fed cuts rates → borrowing becomes cheaper → businesses invest and hire more → jobs are created → unemployment falls

The Bond Market and Interest Rates

Bond prices and interest rates move in opposite directions. When rates rise, existing bonds (paying lower fixed coupons) become less valuable — their prices fall. When rates fall, existing bonds become more attractive — their prices rise.

How Rising Rates Affect the Economy

1. Housing cools: Higher mortgage rates reduce affordability, cutting demand and slowing price growth
2. Borrowing slows: Businesses take on less debt for expansion when rates are high
3. Dollar strengthens: Higher US rates attract foreign investment, raising dollar demand
4. Stock market pressured: Higher rates compete with stocks for investor money and raise corporate borrowing costs
5. Savers rewarded: Bank accounts and bonds finally pay meaningful interest