Banks pay interest because they use your money to make loans and investments

When you deposit money into a savings account, the bank doesn't lock it in a vault with your name on it. The bank lends that money out to other customers as mortgages, car loans, and business loans. The people who borrow pay interest to the bank. The bank keeps some of that interest as profit and pays you a portion of it as savings account interest.

This is the core transaction: you lend money to the bank, the bank lends it to someone else at a higher rate, and you receive a cut. The interest rate the bank offers you depends on how much they can earn by lending your money out, how much competition exists for deposits, and what the Federal Reserve's interest rates are doing.

The bank is not being generous. It is running a business. The interest you earn is the price the bank pays to use your money instead of someone else's.

Key Takeaways

  • Banks lend out the money you deposit and earn interest from borrowers; they pay you a portion of that interest to keep your account open.
  • The interest rate you receive varies by bank, account type, and the current Federal Reserve rate, not by how much money you have deposited.
  • High-yield savings accounts pay more interest than traditional savings accounts because they are offered by online banks with lower operating costs.
  • Interest rates rise when the Federal Reserve raises its benchmark rate and fall when the Fed lowers it, usually within weeks or months.
  • The interest you earn is taxable income and must be reported on your tax return if the total exceeds a certain threshold.

How the Federal Reserve rate affects what your bank pays you

The Federal Reserve sets a target interest rate range that banks use to lend money to each other overnight. This is called the federal funds rate. When the Fed raises this rate, banks' costs go up, and they typically raise the interest rates they offer on savings accounts. When the Fed lowers the rate, banks usually lower savings account rates.

The connection is not instant. Banks may wait weeks or months to change their rates, and different banks move at different speeds. Some banks raise rates quickly when the Fed moves but are slow to lower them when the Fed cuts. Others do the opposite. There is no rule that forces banks to pass along the Fed's changes at all, though competition usually pushes them to do so eventually.

You can track the Federal Reserve's current rate on the Federal Reserve's website. If the Fed is in a rising cycle, you may see your bank's savings rate increase over the coming months. If the Fed is cutting rates, expect your rate to fall.

Why different banks pay different interest rates

Two banks in the same city, facing the same Federal Reserve rate, may offer savings rates that differ by half a percent or more. The difference comes down to how much each bank needs deposits and what it costs them to operate.

Online banks typically pay higher rates than brick-and-mortar banks because they have no physical branches, fewer employees, and lower rent. They can afford to pay you more interest because their costs are lower. A traditional bank with hundreds of branches and thousands of employees has higher expenses and less money left over to pay depositors.

Banks also compete for deposits based on how much money they need. A bank that is growing fast and needs cash may raise its rate to attract new accounts. A bank that already has plenty of deposits may lower its rate because it does not need more money right now. Market conditions, not fairness, set the rate.

How interest compounds and grows your balance

Most savings accounts compound interest daily or monthly. This means the bank calculates interest on your balance, adds it to your account, and then calculates next period's interest on the new, larger balance. You earn interest on your interest.

The math is straightforward. If you have $10,000 in an account earning 4.5% annual interest compounded daily, the bank divides 4.5% by 365 days and calculates interest each day. After one year, you will have roughly $10,450. After two years, roughly $10,920. The longer your money sits, the more the compounding effect adds up.

The exact amount depends on the bank's compounding method and when it credits interest to your account. Some banks compound and credit daily; others compound daily but credit monthly. Read your account agreement to see how your bank handles it. The difference is usually small, but it matters over years.

Interest rates and inflation: why your money may lose buying power

Interest rates and inflation move together but are not the same thing. Inflation is the rate at which prices for goods and services rise. If inflation is 3% and your savings account earns 2%, your money is losing buying power—you can buy less with it next year than you can today, even though the account balance grew.

When inflation is high, the Federal Reserve usually raises interest rates to cool down the economy. When inflation is low, the Fed typically lowers rates. Over long periods, savings account interest rates tend to stay close to inflation, but they do not always match month to month.

This is why some people move money to other accounts or investments when savings rates are very low. A money market account, certificate of deposit, or short-term Treasury bill may offer higher rates during certain periods. None of these are risk-free, but they may preserve buying power better than a savings account when inflation is high.

What happens to interest if you withdraw money early

Regular savings accounts have no penalty for withdrawals. You can take out money at any time and keep all the interest you have earned up to that point. The interest is yours; the bank cannot take it back.

Certificates of deposit (CDs) are different. If you withdraw money from a CD before the term ends, the bank charges an early withdrawal penalty, which is usually a certain number of months' worth of interest. A one-year CD with a three-month penalty means you lose three months of interest if you cash it out early. The penalty is spelled out in your CD agreement before you open the account.

Money market accounts sometimes have limits on how many withdrawals you can make per month without penalty. Check your account agreement to see whether your account has withdrawal restrictions.

How interest income is taxed

The interest your savings account earns is taxable income. At the end of each year, your bank sends you a Form 1099-INT showing how much interest you earned. You report this amount on your federal tax return.

The tax you owe depends on your total income and tax bracket. If you earned $100 in interest and you are in the 22% tax bracket, you owe roughly $22 in federal tax on that interest. State taxes may apply as well, depending on where you live.

If you earned less than $10 in interest during the year, your bank may not send you a Form 1099-INT, but you still owe tax on it if you file a return. Keep your own records of interest earned. Some banks also allow you to link your savings account to a tax software program that pulls the interest amount automatically.

Frequently Asked Questions

Why does my savings account interest rate keep changing?

Your bank changes rates based on what the Federal Reserve does and how much competition exists for deposits. When the Fed raises its benchmark rate, banks usually raise savings rates within weeks or months. When the Fed cuts rates, banks typically lower savings rates. Some banks move faster than others, and some may not pass along the full change.

Is the interest I earn on my savings account may provide?

No. Your bank can lower the interest rate on your savings account at any time, usually with notice. The rate is not locked in unless you open a certificate of deposit, which guarantees a fixed rate for a set term. Savings accounts have variable rates that change with market conditions.

Can I earn interest on money I withdraw before the end of the month?

Yes, in most cases. Banks calculate interest based on your daily balance, so you earn interest on money for each day it sits in the account. If you deposit $5,000 on the first of the month and withdraw it on the fifteenth, you earn interest for fifteen days. The exact amount depends on the interest rate and how the bank compounds interest.

What is the difference between APY and APR on a savings account?

APY (annual percentage yield) includes the effect of compounding and shows what you will actually earn over a year. APR (annual percentage rate) does not include compounding. Banks are required to show you the APY, which is the number that matters for comparing savings accounts. A 4.5% APY will earn you more than a 4.5% APR because of compounding.

Do I have to pay taxes on interest if I earned very little?

If you earned less than $10 in interest, your bank may not send you a Form 1099-INT. However, you still owe tax on it if you file a return. Keep your own records of all interest earned. If you do not file a return, you generally do not owe tax on the interest, but check your specific situation with a tax professional.