Interest is money the bank pays you for keeping your money there

When you deposit money into a savings account, the bank lends that money out to other customers as mortgages, car loans, and business loans. The bank charges those borrowers interest. In return, the bank pays you a portion of what it collects — that payment is called interest on your savings account.

The amount you earn depends on three things: how much money you have in the account, how long it stays there, and the interest rate the bank offers. A higher rate means more money back to you. A lower rate means less. The rate can change at any time, and different banks offer different rates on the same day.

Interest is calculated and added to your account either daily, monthly, or annually, depending on the bank's terms. Most savings accounts compound interest, meaning you earn interest on the interest you've already earned — a small but real advantage over time.

Key Takeaways

  • Interest rates on savings accounts vary by bank and change frequently, so comparing rates across banks can increase what you earn on the same deposit.
  • The interest you earn is calculated based on your account balance, the interest rate, and how often the bank compounds interest (daily, monthly, or yearly).
  • High-yield savings accounts typically pay 4 to 5 times more interest than traditional savings accounts at large banks, though rates shift with federal policy.
  • You owe federal income tax on all interest you earn, and the bank will send you a 1099-INT form at tax time if you earn $10 or more in a year.

How the interest rate is set and why it changes

Banks set their own interest rates, but they follow the lead of the Federal Reserve. When the Federal Reserve raises its benchmark rate, banks typically raise the rates they pay on savings accounts. When the Fed lowers its rate, banks usually lower savings rates too. This happens because banks' own costs of borrowing money change, and they adjust what they pay depositors accordingly.

The rate you see advertised today may not be the rate you earn next month. Banks can change rates without notice, and they often do. Some accounts have a promotional rate that is high for a limited time, then drops to a lower permanent rate. Always read the fine print to see whether the rate is may provide or subject to change.

Online banks and credit unions often pay higher rates than brick-and-mortar banks because they have lower overhead costs. Shopping around takes 15 minutes and can mean the difference between earning $50 and $200 on a $10,000 deposit over a year.

How to calculate what you'll earn

The basic formula is: Interest = Balance × Annual Rate ÷ 365 × Number of Days. If you have $5,000 in an account paying 4.5% annual interest, you earn roughly $225 per year, or about $18.75 per month.

Most banks compound interest daily, which means they calculate what you owe interest on every single day, including the interest from previous days. This compounds your earnings slightly. Over a year, daily compounding on a $5,000 balance at 4.5% yields about $230 instead of $225 — not a huge difference, but real money.

Your bank statement or online account dashboard will show you exactly how much interest you've earned in any given month. You do not have to calculate it yourself. The bank does the math and deposits the interest directly into your account.

The difference between savings accounts and money market accounts

A money market account is a hybrid between a savings account and a checking account. It typically pays a higher interest rate than a regular savings account, but it also allows you to write checks or use a debit card — though usually with limits on how many times per month you can withdraw.

Money market accounts often require a higher minimum balance to open and to earn the advertised rate. If your balance drops below that minimum, the rate drops sharply or you pay a monthly fee. Read the terms carefully before opening one.

For most people, a high-yield savings account pays better interest than a money market account without the minimum balance requirement or withdrawal limits. Money market accounts make sense only if you need check-writing ability and can maintain the minimum balance.

What happens to interest when rates fall

If you opened a savings account when rates were high and rates have since fallen, your rate will fall too — unless you locked in a rate may provide, which is rare. Banks lower rates on existing accounts without asking permission, though they must notify you in advance.

When rates drop, your interest earnings shrink. A $10,000 balance earning 5% yields $500 per year; the same balance at 2% yields only $200. This is why moving money to a higher-paying account makes sense when rates change. You can close one account and open another at a bank offering better terms without penalty.

Some people move money between banks several times a year to chase the highest available rate. This works if you have the time and do not mind the small hassle of opening new accounts. Others prefer to stay put and accept whatever rate their bank offers. Both approaches are reasonable depending on your situation.

Interest income and your taxes

All interest you earn on a savings account is taxable income. You owe federal income tax on it, and most states tax it as well. The bank will send you a Form 1099-INT at tax time if you earned $10 or more in interest during the year.

You report this interest on your tax return as ordinary income. If you earned $200 in interest and you are in the 22% tax bracket, you will owe roughly $44 in federal tax on that interest. This is one reason high-yield accounts matter: earning 4.5% instead of 0.01% means more money left after taxes.

If you did not receive a 1099-INT but earned interest, you still owe tax on it. The bank's failure to send the form does not erase the tax obligation. Keep your own records of interest earned.

Certificates of Deposit as an alternative to savings accounts

A Certificate of Deposit (CD) is a different product from a savings account. You agree to leave your money untouched for a set period — typically three months to five years — and in return the bank pays you a higher interest rate than a savings account offers.

The tradeoff is access. If you withdraw money from a CD before the term ends, you pay a penalty, usually several months' worth of interest. This makes CDs suitable only for money you know you will not need for the full term.

CDs pay a fixed rate for the entire term, so you know exactly what you will earn. This is different from savings accounts, where the rate can change. If rates fall after you open a CD, you keep the higher rate. If rates rise, you are locked in at the lower rate.

Frequently Asked Questions

Can I lose money in a savings account?

No. Your principal — the money you deposit — is protected by the Federal Deposit Insurance Corporation (FDIC) up to $250,000 per account at FDIC-insured banks. Interest rates can fall, so you earn less, but the bank cannot take your deposit. Credit unions offer similar protection through the National Credit Union Administration (NCUA).

Why do online banks pay more interest than big banks?

Online banks have no physical branches, so they spend less on buildings, staff, and overhead. They pass those savings to customers by paying higher interest rates on deposits. The tradeoff is that you cannot walk into a branch to deposit cash or speak to someone in person, though most online banks reimburse ATM fees.

Is interest paid monthly or yearly?

Interest is calculated daily at most banks but paid monthly or quarterly. Some accounts pay annually. Check your account terms to see when interest is deposited. Regardless of when it is paid, you owe income tax on all interest earned in the calendar year.

What if I move my money to a different bank — do I lose the interest I earned?

No. Interest you have already earned stays in your account and moves with you. When you transfer money to a new bank, the interest earned up to that point is yours to keep. Only future interest is affected by the new bank's rate.

How much interest will I earn on $1,000?

It depends on the rate and how long the money stays in the account. At 4.5% annual interest, $1,000 earns about $45 per year, or roughly $3.75 per month. At 0.01%, it earns about 10 cents per year. Rates vary widely, so check your bank's current rate to calculate your specific earnings.