Interest is money the bank pays you for letting them use your money

When you deposit money into a savings account, the bank lends that money 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 keeping your money with them. That payment to you is called interest, and it gets added to your account balance automatically on a schedule set by your bank.

The amount of interest you earn depends on two things: how much money you have in the account and the interest rate the bank offers. A higher rate means more money paid to you. A larger balance means that rate applies to a bigger number. The math is straightforward, but the rates themselves vary widely between banks and change over time based on what the Federal Reserve does with its own rates.

Key Takeaways

  • Banks pay you interest on savings account balances because they lend your money to other customers and keep the difference between what they charge borrowers and what they pay you.
  • Interest rates vary by bank and by account type, and they change when the Federal Reserve adjusts its benchmark rate, usually a few times per year.
  • Interest compounds, meaning you earn interest on your interest, so money in a savings account grows faster the longer it sits untouched.
  • Online banks typically offer higher interest rates than brick-and-mortar banks because they have lower overhead costs.
  • The interest you earn is taxable income and must be reported on your tax return if the total exceeds a certain threshold.

How interest rates are set and why they change

Your bank does not decide its interest rate in isolation. The Federal Reserve, which is the central bank of the United States, sets a target range for the federal funds rate—the rate at which banks lend money to each other overnight. When the Federal Reserve raises or lowers this rate, banks adjust the rates they offer to customers within weeks or months. A higher federal funds rate usually means higher savings account rates. A lower federal funds rate usually means lower savings account rates.

Banks also look at what other banks are offering. If your bank's rate falls too far behind competitors, customers move their money elsewhere. This competition is why online banks often offer higher rates than traditional banks—they have fewer physical branches to maintain, so they can pass more of their profit to depositors as interest.

The rate your specific account earns also depends on the type of account. A regular savings account typically earns less than a money market account or a certificate of deposit (CD). CDs lock your money away for a set period (three months to five years, typically) in exchange for a higher rate. Money market accounts require a higher minimum balance but offer rates between savings and CDs.

How compounding makes your money grow faster

Interest does not just add to your balance once a year. Most banks calculate and add interest monthly or daily. This is called compounding, and it means you earn interest on your interest. After the first month, your balance is slightly larger. The next month, the bank calculates interest on that larger number. Over years, this effect becomes significant.

For example, if you deposit $10,000 at a 4% annual rate compounded monthly, after one year you will have roughly $10,408. After five years, you will have roughly $12,210. The difference between what you earned from simple interest (just 4% of $10,000 each year) and what you earned from compounding grows the longer the money sits. This is why starting early and leaving money untouched matters.

The frequency of compounding varies by bank. Daily compounding grows your money slightly faster than monthly compounding, but the difference is small unless your balance is very large. Check your account details or ask your bank how often interest is compounded on your specific account.

Where to find your account's interest rate and terms

Your bank discloses the interest rate and compounding frequency in a document called the Truth in Savings Disclosure or Deposit Account Agreement. You receive this when you open the account, and you can request it anytime. The document also lists any fees, minimum balance requirements, and conditions under which the rate might change.

You can also find current rates on your bank's website or by calling their customer service line. If you are comparing banks, look for the Annual Percentage Yield (APY), not just the interest rate. APY includes the effect of compounding and gives you a true picture of how much you will earn in a year.

Your monthly or quarterly statement shows the interest you earned that period. If you do not see it, ask your bank whether interest is being credited to your account. Some accounts have minimum balance requirements, and if your balance falls below that threshold, the bank may not pay interest that month.

Interest rates on savings accounts versus other places to keep money

Savings accounts are not the only place money can earn interest. Money market accounts, CDs, and Treasury bills all pay interest, usually at higher rates than savings accounts. The tradeoff is access: a savings account lets you withdraw money anytime without penalty, while a CD locks your money for a set term and charges a fee if you withdraw early.

High-yield savings accounts, offered mostly by online banks, currently pay rates between 4% and 5% annually, depending on the bank and the current interest rate environment. Traditional brick-and-mortar banks often pay 0.01% to 0.5% on regular savings accounts. The difference is enormous over time. A $10,000 balance earning 0.01% grows to $10,001 in a year. The same balance at 4.5% grows to $10,450.

If you are keeping money in a traditional bank account earning less than 1%, moving to a high-yield savings account at an online bank is usually worth the effort. The process takes a few days, and you keep the same Federal Deposit Insurance Corporation (FDIC) protection that covers up to $250,000 per account.

What happens to interest when rates change

When the Federal Reserve changes its benchmark rate, your bank's savings rate will change too, but not necessarily on the same day. Most banks adjust rates within a few weeks. Some banks raise rates quickly when the Fed raises its rate, but lower rates slowly when the Fed cuts. Read your account agreement to see whether your bank can change your rate without notice.

If rates drop and your bank lowers your rate, you have the option to move your money to a bank offering a better rate. If rates rise and your bank raises your rate, you benefit automatically. This is why it makes sense to check rates periodically, especially after the Federal Reserve announces a rate change. Rates that were competitive six months ago may no longer be.

How interest income affects your taxes

Interest you earn on a savings account is taxable income. If your account earned $10 or more in interest during the year, your bank will send you a Form 1099-INT in January. You must report this income on your tax return, even if the amount is small.

The interest is taxed at your ordinary income tax rate, which is higher than the capital gains rate. This means a savings account earning 4% interest is not the same as an investment earning 4% in capital gains. The tax burden is heavier. However, the interest is still real income, and the tax is only owed on money you actually earned, not on your original deposit.

If you earned less than $10 in interest, your bank may not send a Form 1099-INT, but you are still required to report the income if you file a tax return. Keep your own records of interest earned if the amount is small.

Frequently Asked Questions

How often does interest get added to my account?

Most banks calculate interest daily or monthly and add it to your balance on a monthly or quarterly schedule. Check your account agreement or call your bank to find out the exact frequency. The more often interest is compounded, the more you earn, but the difference is usually small unless your balance is very large.

Can I lose money in a savings account?

No, as long as your balance stays within the FDIC insurance limit of $250,000. The bank cannot take money from your account without your permission. Interest rates can fall, so you earn less, but your original deposit is always safe. The only way to lose money is if you withdraw more than you deposited.

Why do some banks offer much higher interest rates than others?

Online banks have lower overhead costs than banks with physical branches, so they can offer higher rates and still make a profit. Both types of banks are equally safe as long as they are FDIC-insured. The higher rate at an online bank is real—you are not taking on extra risk by moving your money there.

What is the difference between APR and APY?

APR (Annual Percentage Rate) is the interest rate alone. APY (Annual Percentage Yield) includes the effect of compounding. APY is always equal to or higher than APR. When comparing savings accounts, always use APY, because it shows the true amount you will earn in a year.

Does my interest rate stay the same forever?

No. Banks can change rates anytime, usually within a few weeks of a Federal Reserve rate change. Your account agreement explains whether the bank can change your rate without notice. If rates drop and you want a better rate, you can move your money to another bank.