Interest is money your bank pays you for keeping money in your account

When you deposit money into a savings account, the bank lends that money to other customers through mortgages, car loans, and business loans. In exchange, the bank pays you interest — a percentage of your balance that gets added to your account on a regular schedule. The more money you keep in the account and the higher the interest rate, the more you earn.

The amount you earn depends on three things: your account balance, the interest rate the bank offers, and how often the bank compounds the interest (adds it back into your account so you earn interest on the interest). A bank might offer 4.5% annual percentage yield (APY) on one account and 0.01% on another. The difference between these two rates means hundreds or thousands of dollars over a year if you have a substantial balance.

You do not have to do anything to earn interest once your account is open. The bank calculates and deposits it automatically according to the terms of your account.

Key Takeaways

  • Banks pay interest as a percentage of your balance, and the rate varies widely between banks and account types — comparing rates before opening an account matters.
  • Annual Percentage Yield (APY) tells you the actual rate you will earn in a year, including how often interest compounds.
  • High-yield savings accounts typically pay 4% to 5% APY, while traditional savings accounts often pay less than 0.5% APY.
  • Interest is taxable income, and your bank will send you a Form 1099-INT if you earn $10 or more in a year.
  • Moving money between accounts or closing an account does not affect interest you have already earned, but it stops future interest from accruing.

How to compare interest rates before opening an account

Banks publish their interest rates on their websites, usually on the savings account product page. Look for the Annual Percentage Yield (APY), not just the interest rate — APY includes how often the bank compounds interest, so it shows you the real return you will get in a year. A bank advertising 4.5% APY will pay you more than one advertising 4.5% interest rate compounded quarterly.

Interest rates change frequently, sometimes weekly. If a bank is offering 4.8% APY today, it may drop to 4.5% next month. There is no penalty for moving your money to a higher-rate account, so if you see a rate you like, opening an account quickly makes sense — but do not rush into an account with a poor rate just because you are in a hurry.

Online banks typically offer higher rates than brick-and-mortar banks because they have lower overhead costs. A traditional bank might pay 0.01% APY while an online bank pays 4.5% APY on the same type of account. The tradeoff is that online banks do not have physical branches, so deposits and withdrawals happen by mail, mobile app, or electronic transfer.

How interest compounds and grows your balance over time

Compounding means the bank adds interest to your account, and then you earn interest on that interest in the next period. If you have $10,000 in an account earning 4.5% APY compounded daily, the bank calculates one day's worth of interest (about $1.23), adds it to your balance, and the next day you earn interest on $10,001.23 instead of $10,000. Over a year, daily compounding earns you more than monthly or quarterly compounding at the same rate.

The difference between compounding frequencies is small for most balances. On $10,000 at 4.5% APY, daily compounding earns about $461 in a year, while monthly compounding earns about $460. On $100,000, the difference is roughly $10. The bigger factor is the APY itself — moving from 0.5% to 4.5% APY on $10,000 means earning $400 more per year.

You can calculate what your balance will be after a year using the formula: Final Balance = Starting Balance × (1 + APY). If you start with $10,000 at 4.5% APY, your balance after one year will be $10,000 × 1.045 = $10,450. This assumes you do not add or withdraw money during the year.

When interest is deposited into your account

Banks deposit interest on different schedules. Some add it monthly, some quarterly, and some daily (though daily deposits are rare — most banks that compound daily deposit the interest monthly). Check your account agreement or the product page to see when your bank deposits interest. The schedule does not affect how much you earn in a year — a 4.5% APY account earns the same total whether interest is deposited monthly or quarterly.

You can watch interest accumulate by logging into your account online or through the mobile app. Some banks show a running total of interest earned year-to-date. If your bank does not display this, you can calculate it yourself by subtracting your opening balance from your current balance and subtracting any deposits or withdrawals you made.

Tax reporting and what you owe on interest earnings

Interest you earn is taxable income. If you earn $10 or more in interest during a calendar year, your bank will send you a Form 1099-INT by January 31 of the following year. You report this income on your federal tax return, and you may owe federal income tax on it. Some states also tax interest income.

The tax you owe depends on your total income and tax bracket. If you earn $500 in interest and you are in the 22% tax bracket, you will owe roughly $110 in federal income tax on that interest (the actual amount depends on your full tax situation). This is one reason high-yield savings accounts matter — earning 4.5% instead of 0.5% on $10,000 means $400 more in your pocket even after taxes.

Keep records of your interest earnings if you want to track them throughout the year. Your bank's online portal usually shows year-to-date interest earned, and you can screenshot or download this for your records.

Why interest rates vary between banks and account types

Banks set their own interest rates based on what the Federal Reserve charges them to borrow money, how much competition they face, and how much they need deposits. When the Federal Reserve raises its benchmark rate, banks eventually raise savings account rates — but not always by the same amount, and not always immediately. Some banks raise rates quickly to attract deposits; others lag behind.

Different account types within the same bank pay different rates. A money market account might pay 4.6% APY while a regular savings account pays 4.2% APY. A certificate of deposit (CD) might pay 5.0% APY if you agree to lock your money away for six months or a year. These differences reflect how the bank uses the money and how much flexibility you have to withdraw it.

Credit unions sometimes offer higher rates than banks because they are member-owned and do not have shareholders demanding profits. If you are a member of a credit union, comparing their savings rates to online banks is worth doing.

What happens to interest if you move or close your account

Interest you have already earned belongs to you and stays in your account when you move money or close the account. If you earned $50 in interest before closing the account, that $50 is yours — the bank does not take it back. However, once you close the account, you stop earning interest on any remaining balance.

If you transfer money from one bank to another, the interest you earned at the first bank stays there (or is transferred with your balance if you move the whole account). You start earning interest at the new bank on whatever balance you deposit there. There is no waiting period or penalty — interest starts accruing immediately at the new bank.

Frequently Asked Questions

Can I earn interest on a checking account?

Some checking accounts pay interest, but the rates are almost always much lower than savings accounts — often 0.01% to 0.5% APY. If you want to earn meaningful interest, a dedicated savings account or money market account is a better choice. Keep your checking account for spending and your savings account for money you want to grow.

What is the difference between APY and interest rate?

Interest rate is the percentage the bank pays, while APY (Annual Percentage Yield) includes how often interest compounds. APY shows you the real amount you will earn in a year. Always compare APY, not interest rate, when choosing between accounts.

Do I lose interest if I withdraw money before the end of the year?

No. You earn interest on whatever balance you have each day. If you have $10,000 for six months and then withdraw it, you earn interest only on those six months of balance. You do not forfeit interest you have already earned.

Why do some banks pay almost no interest?

Banks with low rates often have lower overhead costs built into their business model, or they prioritize lending over deposits. Online banks and credit unions typically pay higher rates because they compete for deposits. If your current bank pays less than 1% APY, moving to a higher-rate account could earn you hundreds of dollars per year on the same balance.

Is interest from a savings account considered income for government benefits?

Interest earned is counted as income for some means-tested benefits like Supplemental Security Income (SSI) or certain housing programs. If you receive benefits, check with the program administrator about how interest affects your status. The amount is usually small enough not to matter, but it is worth confirming.