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 your account interest. The more money you keep in the account and the longer you keep it there, the more interest you earn.

The bank tells you the interest rate as an Annual Percentage Yield (APY). This is the percentage of your balance you will earn over one year if you make no deposits or withdrawals. For example, if your account has an APY of 4.50% and you keep $10,000 in it for a full year without touching it, you will earn roughly $450 in interest (though the actual amount depends on how often the bank compounds the interest, which we cover below).

Interest rates vary widely. Online banks often offer higher APYs than brick-and-mortar banks because they have lower overhead costs. Traditional banks may offer 0.01% APY or less, while online savings accounts currently range from 4% to 5.35% APY depending on the bank and market conditions. Rates change over time as the Federal Reserve adjusts its benchmark rate.

Key Takeaways

  • The bank pays you interest because it lends out your deposits to other customers and keeps a portion of what it collects.
  • APY (Annual Percentage Yield) tells you what percentage of your balance you will earn in interest over one year.
  • Compounding means the bank calculates interest on your interest, so your balance grows faster than simple math would suggest.
  • Online banks typically offer higher interest rates than traditional banks, though rates fluctuate with Federal Reserve policy.
  • Interest is taxable income, and you will receive a 1099-INT form from the bank if you earn $10 or more in a year.

How compounding makes your money grow faster

Banks do not wait until the end of the year to pay you interest. Instead, they calculate and add interest to your account at regular intervals — daily, monthly, or quarterly, depending on the bank. Each time interest is added, the next calculation includes that new interest as part of your balance. This is called compounding, and it means you earn interest on your interest.

Here is a concrete example. Suppose you have $10,000 in an account with a 4.50% APY that compounds daily. The bank divides the annual rate by 365 days (4.50% ÷ 365 = 0.0123% per day). On day one, it calculates interest on $10,000 and adds roughly $1.23 to your account. On day two, it calculates interest on $10,001.23 — the original balance plus the interest earned. This continues every day for the year. By the end of the year, you will have earned approximately $460 instead of exactly $450, because you earned interest on the interest.

The more frequently a bank compounds interest, the more you earn. Daily compounding beats monthly compounding, which beats quarterly compounding. Most online banks compound daily, which is why they often advertise their APY prominently — it reflects the benefit of frequent compounding.

Where to find the interest rate before you open an account

Banks display the APY on their website, usually on the savings account product page or in a comparison table. The APY must be shown clearly under federal law (Regulation DD), so you can compare rates across banks before you decide where to open an account.

The APY you see today may not be the rate you earn forever. Banks can change rates at any time, and they often lower rates when the Federal Reserve cuts its benchmark rate. Some banks offer promotional rates that are higher for a limited time (usually three to six months) and then drop to a standard rate. Read the fine print to see whether the rate you are looking at is permanent or temporary.

You can track current rates across banks using comparison websites like Bankrate, DepositAccounts, or NerdWallet. These sites update rates frequently and let you filter by features like minimum balance requirements or FDIC insurance status.

How interest is calculated and when you see it in your account

The bank uses this formula: (Balance × APY ÷ 365) × number of days. If your balance changes during the month — because you make a deposit or withdrawal — the calculation adjusts for those changes. Some banks use the average daily balance method, which adds up your balance for each day of the month and divides by the number of days. Others use the daily balance method, which calculates interest on the exact balance each day.

Interest typically posts to your account monthly, though some banks post it daily or quarterly. When it posts, you will see it as a deposit in your transaction history. The amount will be small — usually a few dollars per month on a typical balance — but it adds up over time, especially if you leave the money untouched.

Interest is taxable income you must report

The interest you earn is considered taxable income by the IRS. 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 must include this amount on your tax return.

If you earn less than $10, the bank does not have to send a form, but you are still required to report the interest on your taxes. Keep your own records of interest earned if the amount is small.

The tax rate you pay on interest depends on your overall income and tax bracket. Interest is taxed as ordinary income, not as capital gains, so it is taxed at your regular income tax rate (which could be 10%, 12%, 22%, or higher depending on your situation).

Why some accounts offer higher rates than others

Online banks offer higher rates because they have lower costs. They do not maintain physical branches, do not employ as many staff members, and do not spend money on building maintenance. They pass those savings to customers through higher interest rates.

Traditional banks with physical locations often offer lower rates because their operating costs are higher. However, some people prefer traditional banks for the ability to walk in and speak to a person, or because they already have other accounts there.

Credit unions sometimes offer competitive rates on savings accounts, especially if you are a member. Rates at credit unions vary by institution, so it is worth checking what your local credit union offers.

Money market accounts and certificates of deposit (CDs) sometimes offer higher rates than regular savings accounts, but they come with trade-offs. Money market accounts may require a higher minimum balance or limit the number of withdrawals you can make per month. CDs lock your money away for a set period (three months to five years) and charge a penalty if you withdraw early.

What happens to your interest if you withdraw money early

Interest accrues (builds up) daily, but it only posts to your account at intervals set by the bank — usually monthly. If you withdraw money before interest posts, you lose the interest that has accrued since the last posting date.

For example, if your bank posts interest on the first of each month and you withdraw $5,000 on the 15th, you will not receive interest on that $5,000 for the partial month it was in the account. The interest calculation for the month will be based on your balance for only the first 15 days.

This is different from early withdrawal penalties, which some accounts charge if you remove money within a certain timeframe. Most regular savings accounts do not have early withdrawal penalties, but money market accounts and CDs do. Check your account terms to see whether withdrawals trigger any penalties.

Frequently Asked Questions

Can I lose money in a savings account?

No. The bank cannot take money from your account without your permission, and FDIC insurance protects your balance up to $250,000 if the bank fails. However, if interest rates fall, the interest you earn will be lower, so your money grows more slowly than it would in a higher-rate environment.

Is the APY the same as the interest rate?

Not exactly. The interest rate is the percentage the bank pays, but APY includes the effect of compounding. APY is always equal to or higher than the interest rate because it accounts for interest earned on interest. Banks must show you the APY so you can compare accounts fairly.

What if I make multiple deposits throughout the year?

Each deposit earns interest from the day it is deposited. If you deposit $5,000 on January 1 and another $5,000 on July 1, the first $5,000 earns interest for the full year, while the second $5,000 earns interest for only six months. The bank calculates this automatically.

Do I have to do anything to earn interest?

No. Once you open the account and deposit money, interest accrues automatically. You do not need to take any action. The bank handles all calculations and deposits the interest into your account on its schedule.

What happens to my interest if I close the account?

You receive all interest that has posted to your account up to the closing date. Interest that has accrued but not yet posted may or may not be paid, depending on the bank's policy. Ask the bank before you close the account if you want to know whether you will receive accrued-but-unposted interest.