What you earn depends on the rate your bank offers and how much you have saved

The amount of interest a savings account earns is determined by two things: the annual percentage yield (APY) the bank advertises, and the balance you keep in the account. A bank offering 4.5% APY on $10,000 will pay you roughly $450 per year in interest. A bank offering 0.01% APY on the same $10,000 will pay you about $1 per year. The difference between these two scenarios is real money — and it matters whether you shop around or simply accept whatever rate your current bank offers.

Interest compounds, meaning you earn interest on your interest. If your bank compounds daily (the most common method), the interest gets added to your balance each day, and tomorrow's interest calculation includes today's interest. This compounds your earnings over time, though the effect is small on shorter timescales. Over years, it becomes meaningful.

The rate you see advertised is not may provide to stay the same. Banks change their rates regularly, usually in response to changes in the federal funds rate set by the Federal Reserve. When the Fed raises rates, banks typically raise savings rates. When the Fed cuts rates, banks typically cut savings rates — sometimes quickly, sometimes slowly. Your bank's rate today may not be your bank's rate in six months.

Key Takeaways

  • Interest earned equals the APY multiplied by your balance, divided by 365 days, then compounded daily — so a higher rate and a larger balance both increase what you earn.
  • Banks change their rates regularly based on Federal Reserve decisions, so the rate you see today may drop without warning.
  • High-yield savings accounts at online banks typically pay 4% to 5% APY, while traditional brick-and-mortar banks often pay 0.01% to 0.05% APY for the same type of account.
  • The difference between a 0.01% account and a 4.5% account on $50,000 is roughly $2,250 per year in lost earnings.
  • Your interest is taxed as ordinary income, so you will owe federal income tax on whatever your account earns.

How the math works: calculating your actual earnings

The formula for interest earned is straightforward: Balance × APY ÷ 365 = Daily Interest. If you have $25,000 in an account earning 4.5% APY, you earn roughly $3.08 per day. Over a year, that adds up to about $1,125 in interest (before taxes).

Most banks compound interest daily, which means they calculate the interest owed each day and add it to your balance. The next day's calculation includes that added interest. Over a full year, daily compounding produces slightly more earnings than simple interest would, but the difference is usually a few dollars on typical account sizes.

The APY you see advertised already accounts for compounding, so you do not need to do a separate calculation. You can trust that 4.5% APY means you will earn approximately 4.5% of your balance over the course of a year, assuming the rate does not change and you do not withdraw money.

Why rates vary so much between banks

A traditional bank with physical branches — the kind with a building on Main Street — typically pays 0.01% to 0.05% APY on savings accounts. An online bank with no branches typically pays 4% to 5.5% APY on the same type of account. The difference is not because one bank is generous and the other is stingy. It is because online banks have lower overhead costs. They do not maintain buildings, pay tellers, or operate call centers. They pass those savings to customers through higher interest rates.

Traditional banks can afford to pay lower rates because many customers stay with them out of habit or convenience, even when better rates are available elsewhere. Online banks must offer competitive rates to attract customers who have no reason to choose them except the rate itself.

Some banks also offer promotional rates for new accounts — for example, 5.35% APY for the first three months, then a lower rate afterward. Read the fine print to see when the promotional period ends and what the regular rate will be.

How federal interest rate changes affect what you earn

The Federal Reserve sets a target range for the federal funds rate, which is the interest rate banks charge each other for overnight loans. When the Fed raises this rate, banks typically raise the rates they offer on savings accounts. When the Fed cuts the rate, banks typically cut savings rates.

The lag between a Fed decision and a change in your savings rate varies. Some online banks raise rates within days of a Fed increase. Others take weeks. When the Fed cuts rates, banks often cut savings rates faster than they raise them — sometimes within a few days. This asymmetry means your rate may drop quickly but rise slowly.

If you lock in a high rate now, that rate will eventually fall as the Fed cuts rates in the future. There is no way to predict when that will happen, but it is a normal part of how savings accounts work. The rate you earn today is not the rate you will earn forever.

The difference between APY and APR

APY (annual percentage yield) is what banks use for savings accounts. It includes the effect of compounding, so it shows the true annual return. APR (annual percentage rate) is used for loans and credit cards. It does not include compounding.

For savings accounts, always look at the APY, not the APR. The APY is the number that tells you what you will actually earn. If a bank advertises both, the APY will be slightly higher than the APR because of compounding, but the difference is small on savings accounts.

How taxes reduce your interest earnings

Interest earned in a savings account is taxed as ordinary income. If you earn $1,000 in interest and you are in the 22% federal tax bracket, you will owe $220 in federal income tax on that interest. You may also owe state income tax, depending on where you live.

This means your true after-tax earnings are lower than the APY suggests. A 4.5% APY account earning $1,000 in interest becomes $780 in after-tax earnings if you are in the 22% bracket. This is one reason why even small differences in APY matter — a 0.5% difference in rate can mean hundreds of dollars in after-tax earnings over a year on a large balance.

You do not pay taxes on the interest until you file your tax return, but the interest is still taxable income in the year it was earned. Your bank will send you a 1099-INT form in January showing how much interest you earned the previous year.

Comparing what different account types earn

A regular savings account at an online bank typically earns 4% to 5.5% APY. A money market account at an online bank typically earns the same rate or slightly higher. A certificate of deposit (CD) locks your money away for a set period — three months, one year, five years — and usually pays a higher rate in exchange for that restriction. A high-yield savings account is simply a savings account that pays a higher rate; the term "high-yield" is marketing language, not a legal category.

The account type matters less than the rate and the bank. An online bank's regular savings account earning 4.5% will earn you more money than a traditional bank's "premium" savings account earning 0.05%, even though the traditional bank's account sounds fancier.

Frequently Asked Questions

How often is interest added to my account?

Most banks compound and add interest daily, though some compound monthly or quarterly. Daily compounding produces slightly more earnings, but the difference is small — usually a few dollars per year on typical balances. Your bank's disclosure documents will state the compounding frequency.

Can I lose money in a savings account?

No. A savings account cannot have negative returns. In the worst case, you earn 0% interest, but your principal stays intact. Your account is also insured by the FDIC up to $250,000, so even if the bank fails, your money is protected.

What happens to my interest if I withdraw money mid-year?

You earn interest only on the balance you actually held. If you had $10,000 for six months and then withdrew it all, you earn interest on $10,000 for six months, not for the full year. Some accounts charge a penalty for early withdrawal, so check your bank's terms before moving money.

Is there a minimum balance required to earn interest?

Most online banks do not require a minimum balance to earn the advertised rate. Some traditional banks require $500 or $1,000 minimum to earn any interest at all, or to earn the higher rate. Check your bank's terms — this is one more reason online banks often pay better rates.

Should I move my money to a higher-rate account?

If your current bank pays 0.01% and an online bank pays 4.5%, the difference in earnings is substantial enough to justify the move. Opening an online savings account takes 10 minutes and involves no fees. The main inconvenience is that online banks do not have branches, but for a savings account you are not using for daily transactions, this is rarely a problem.