Your savings account interest depends on the bank's rate and how much money you have in the account

The amount of interest you earn is not fixed — it changes based on two things: the Annual Percentage Yield (APY) your bank offers, and the balance you keep in the account. A bank might advertise a 4.5% APY, but that is the rate they are offering right now. That rate can go up or down, and different banks offer different rates for the same type of account.

To find out what you will actually earn, you need to know your bank's current APY and your account balance. Then you multiply them together. If you have $5,000 in an account earning 4.5% APY, you would earn roughly $225 in a year — though the actual amount depends on how often the bank compounds the interest (adds it back into your account).

The tricky part is that APY rates change frequently, especially when the Federal Reserve changes its benchmark rate. Your bank might offer 4.5% today and 3.8% next month. Some banks raise rates to attract new customers, then lower them once the money is deposited. Reading your account statements and checking your bank's website regularly is the only way to know what you are actually earning right now.

Key Takeaways

  • Your interest earnings equal your account balance multiplied by the APY your bank is currently offering, divided by 12 if you want a monthly estimate.
  • APY rates vary by bank and change frequently, so the rate advertised online may not be the rate you locked in when you opened your account.
  • High-yield savings accounts at online banks typically pay more interest than traditional savings accounts at brick-and-mortar banks.
  • Interest compounds — usually daily or monthly — which means you earn interest on the interest you already earned, though the difference is small in savings accounts.
  • Your bank statement shows the actual interest you earned that month, so you can verify the calculation yourself.

How banks calculate the interest you earn

Banks use a formula that looks like this: (Balance × APY) ÷ 365 × number of days the money sat in the account. That gives you the interest for one period. Most banks compound daily, meaning they calculate interest each day and add it to your balance, so the next day's calculation includes that new interest.

In practice, you do not have to do this math yourself. Your bank calculates it and deposits the interest into your account automatically, usually monthly. You can see the exact amount on your statement under a line that says "Interest Earned" or "Interest Paid."

The reason compounding matters is that once interest is added to your account, it starts earning interest too. If you earn $18 in interest one month, that $18 now earns interest the next month. Over a year, this adds up — though in a savings account, the difference between daily compounding and monthly compounding is usually just a few dollars on a typical balance.

Why different banks pay different rates

Banks set their own APY based on what they need to attract deposits and what they can afford to pay. Online banks typically offer higher rates than traditional banks because they have lower overhead costs — no physical branches, fewer employees, less expensive real estate. They pass those savings to customers in the form of higher interest rates.

Banks also adjust rates based on what the Federal Reserve does. When the Fed raises its benchmark rate, banks usually raise savings account rates too. When the Fed lowers rates, banks follow. However, banks do not always move at the same speed or by the same amount, so you might see one bank offer 4.5% while another offers 3.8% for the same type of account.

Promotional rates also affect what you see advertised. A bank might offer 5.0% APY for the first three months to attract new customers, then drop to 3.5% after that. Always read the fine print to see whether a rate is temporary or permanent.

How to compare what different banks are paying

The best way to compare is to visit each bank's website and look for the current APY on their savings account product page. Write down the rate, the account type (regular savings, high-yield savings, money market), and any restrictions (like minimum balance requirements). Then compare side by side.

Websites like Bankrate, DepositAccounts, and the FDIC's National Rates and Rate Caps tool let you see rates from multiple banks at once. These sites update frequently, though not always when ready, so the rate you see might have changed by the time you visit the bank's website.

When you compare, pay attention to the account type, not just the rate. A high-yield savings account at an online bank might pay 4.5%, while a money market account at the same bank might pay 4.8%. They are different products with different features, so the higher rate might come with restrictions you do not want.

What happens to your interest if you withdraw money

If you withdraw money partway through the month, you earn interest only on the balance that stayed in the account for the full period. Banks calculate this using the "daily balance method" — they track your balance each day and average it over the month, then explore the APY to that average.

For example, if you had $10,000 in the account for 20 days and $5,000 for 10 days, your average balance for the month is roughly $8,333. The bank applies the APY to that average, not to your opening balance. This is why keeping money in the account longer earns you more interest.

Some banks have minimum balance requirements, and if your balance drops below that minimum, they may charge a fee or lower your APY. Always check your account agreement to see whether your bank has these rules.

The difference between APY and APR

APY (Annual Percentage Yield) includes compounding — it is the real rate you earn when interest is added back into your account and starts earning interest itself. APR (Annual Percentage Rate) does not include compounding; it is just the straightforward interest rate without the effect of interest on interest.

For savings accounts, banks are required by law to advertise APY, not APR. This is good for you because APY is always higher than APR when compounding happens, so you know the real number you are earning. For loans and credit cards, lenders advertise APR, which works the opposite way — a higher APR means you pay more.

You will almost never see APR used for savings accounts, so if you are looking at a savings product, the number you see is the APY and it already includes the effect of compounding.

How inflation affects what your interest actually buys you

Interest earnings are only part of the picture. If inflation is running at 3% and your savings account earns 4.5% APY, your money is growing faster than prices are rising — you are ahead. But if inflation is 5% and you are earning 4.5%, your money is losing purchasing power even though the account balance is growing.

This is why comparing your APY to the current inflation rate matters. A 4.5% rate sounds good until you realize that prices are rising at 5%, which means the things you want to buy are getting more expensive faster than your savings are growing. You are not losing money in absolute terms, but you are losing it in real terms.

Checking the inflation rate is straightforward — the U.S. Bureau of Labor Statistics publishes it monthly. Comparing that number to your savings account APY tells you whether your money is keeping up with rising prices or falling behind.

Frequently Asked Questions

Can I earn more interest by moving my money to a different bank?

Yes, if another bank is offering a higher APY. The difference adds up over time. Moving $10,000 from a 1% account to a 4.5% account means earning an extra $350 per year. However, factor in any fees for closing your old account or minimum balance requirements at the new bank before you move.

What if my bank lowers the interest rate on my account?

Banks can lower rates at any time without your permission. You have no obligation to stay — you can move your money to another bank offering a higher rate. Some people move their money every few months to chase the highest available rate, though this takes time and effort.

Do I have to pay taxes on the interest I earn?

Yes. Interest earned in a savings account is taxable income. Your bank will send you a 1099-INT form at the end of the year showing how much interest you earned, and you report that on your tax return. The amount is usually small unless you have a large balance or a very high APY.

Is my interest safe if the bank fails?

Yes. The FDIC (Federal Deposit Insurance Corporation) insures savings accounts up to $250,000 per person per bank. This means if the bank fails, the FDIC will pay you back, including any interest you earned up to that point. Check that your bank is FDIC-insured before you open an account.

Why does my bank statement show less interest than I calculated?

The most common reason is that the APY changed during the month, or your balance fluctuated. Banks use the daily balance method, so if your balance was lower for part of the month, you earned less. Also, the advertised rate might be for new customers only — your account might be earning a lower promotional rate that has expired.