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 on those loans. The bank then pays you a portion of that interest as a reward for letting them use your money. That payment to you is called savings account interest.

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 interest rate means you earn more. A larger balance means you earn more. Money that sits in the account longer earns more interest than money that moves out quickly.

Interest rates on savings accounts change. Banks set their own rates based on what the Federal Reserve does with its benchmark rate. When the Fed raises rates, banks usually raise savings rates. When the Fed lowers rates, banks usually lower savings rates too. This means the interest rate you see today might be different three months from now.

Key Takeaways

  • Banks pay you interest on savings account balances because they lend your money to other customers and keep most of the interest those borrowers pay.
  • Your interest earnings depend on your account balance, the bank's interest rate, and how long your money stays in the account.
  • Interest rates vary by bank and change over time based on Federal Reserve decisions, so comparing rates between banks can increase what you earn.
  • Most savings accounts use daily compounding, which means interest is calculated and added to your balance every day, and then you earn interest on that interest.
  • You pay income tax on the interest you earn, and the bank will send you a 1099-INT form if you earn $10 or more in a year.

How the interest rate is expressed and what it actually means

Banks advertise their savings rates as an Annual Percentage Yield (APY). This is the percentage of your balance you will earn in one year if the rate stays the same and you do not withdraw any money. If a bank offers 4.50% APY and you have $10,000 in the account for a full year with no withdrawals, you will earn $450 in interest.

APY is different from Annual Percentage Rate (APR), which you will see on loans. APY includes the effect of compounding (explained below), while APR does not. When comparing savings accounts, always look at the APY, not the APR.

The APY you see advertised is the rate the bank is currently offering to new deposits. If you opened an account six months ago at a different rate, your money might be earning a lower or higher APY depending on what has happened since. Some banks keep old customers on old rates; others move everyone to the current rate. Check your account statement or call your bank to find out what rate you are actually earning right now.

Compounding: earning interest on your interest

Most savings accounts use daily compounding. This means the bank calculates how much interest you have earned each day, adds that interest to your balance, and then calculates the next day's interest on the new, larger balance. You earn interest on the interest you earned yesterday. Over time, this compounds and grows your money faster than if interest were calculated only once a year.

The difference between daily compounding and annual compounding is small on a savings account but becomes larger the longer your money sits there. On a $10,000 balance at 4.50% APY, daily compounding earns you about $450 in a year. Annual compounding would earn you the same $450 in that first year, but if you left the money untouched for five years, daily compounding would earn you noticeably more because each day's interest gets added to the balance before the next day's interest is calculated.

Some savings accounts compound monthly or quarterly instead of daily. Daily compounding is better for you, so if you are comparing accounts, check how often each one compounds.

How to calculate what you will earn

To estimate your interest earnings, use this simple formula: Balance × APY ÷ 365 × Number of Days. This gives you an approximate figure because it does not account for compounding, but it is close enough for planning.

For example: You have $5,000 in an account earning 4.00% APY. You want to know how much you will earn in 90 days. The math is: $5,000 × 0.04 ÷ 365 × 90 = $49.32. The actual amount will be slightly higher because of daily compounding, but $49 is a reasonable estimate.

If you want a more precise number, most banks have an interest calculator on their website. You enter your balance, the APY, and how long you plan to keep the money there, and it shows you the exact amount you will earn with compounding included.

Why interest rates vary so much between banks

Online banks typically offer higher interest rates than brick-and-mortar banks. This is because online banks have lower overhead costs—they do not pay for physical branches, tellers, or as many employees. They pass those savings on to customers by paying higher rates on savings accounts.

Traditional banks with many branches often pay lower rates because their costs are higher. They use the difference between what they pay you and what they charge borrowers to cover their expenses and make a profit.

Credit unions sometimes offer competitive rates, especially if you are a member. Shop around before opening an account. A difference of 1.00% APY on a $10,000 balance means $100 more per year in your pocket. Over five years, that difference compounds to real money.

What happens to your interest if you withdraw money early

If you withdraw money from your savings account before the end of the year, you still earn interest on the money that was there. Interest accrues daily, so you earn a proportional amount based on how long your money was in the account. If you deposit $5,000 on January 1 and withdraw it on July 1, you earn interest for six months, not the full year.

Some savings accounts have no penalties for withdrawals. Others, particularly high-yield savings accounts offered by some banks, may charge a small fee if you make too many withdrawals in a month. Federal rules used to limit savings account withdrawals to six per month, but that rule was suspended in 2020 and has not been reinstated. Still, check your account agreement to see if your bank has its own withdrawal limits or fees.

Money Market Accounts and Certificates of Deposit (CDs) are different. CDs charge a penalty if you withdraw before the maturity date. Money Market Accounts may have withdrawal limits. If you think you might need the money, a regular savings account is usually the better choice.

Taxes on savings account interest

The interest you earn on a savings account is taxable income. You must report it on your federal tax return. If you earn $10 or more in interest during a calendar year, the bank will send you a Form 1099-INT by January 31 of the following year. You use this form to report the interest on your tax return.

The tax you owe depends on your overall income and tax bracket. If you are in the 22% tax bracket and earn $450 in interest, you will owe roughly $99 in federal income tax on that interest. State income tax may apply too, depending on where you live.

This is one reason high-yield savings accounts matter. If you earn 4.50% APY instead of 0.01% APY, you earn more interest before taxes take their share. The after-tax earnings are still higher even though you pay more tax on the larger amount.

Frequently Asked Questions

Does my interest rate stay the same forever?

No. Banks change their rates based on Federal Reserve decisions and market conditions. Your rate can go up or down. Some banks move all customers to the new rate; others keep existing customers on their old rate. Check your account statement or contact your bank to see if your rate has changed.

What is the difference between a savings account and a money market account?

Money Market Accounts often pay higher interest rates than savings accounts, but they usually require a larger minimum balance and may limit how many withdrawals you can make per month. Savings accounts are more flexible. If you need to access your money regularly, a savings account is usually the better choice.

Can I move my money to a different bank if I find a higher rate?

Yes. You can withdraw your money from one bank and deposit it into another at any time. There is no penalty for switching banks with a savings account. You will earn interest at the new bank's rate going forward. Just be aware that the transfer itself takes a few business days, so your money will not be earning interest during that time.

What if my bank's interest rate drops to almost nothing?

If your bank lowers its rate significantly, you can move your money to a bank offering a higher rate. Interest rates on savings accounts change based on Federal Reserve policy, so if rates are low across the board, your options may be limited. But there are usually banks paying more than others, so shopping around is worth your time.

How often is interest added to my account?

Interest is calculated daily at most banks, but it is usually credited to your account monthly. This means you see the interest payment show up in your balance once a month, even though it was being calculated and compounded every day. Check your account statement to see when interest is posted.