APY is the real interest rate you earn on your savings in a year

APY stands for Annual Percentage Yield. It tells you how much money your savings account will earn over one year, including the effect of compounding — when the bank pays interest on the interest you've already earned.

If a savings account offers 4.50% APY and you deposit $1,000, you won't earn exactly $45 by the end of the year. You'll earn slightly more, because the bank calculates and adds interest multiple times during the year (usually daily or monthly), and then pays interest on that new total. APY accounts for that compounding effect and shows you the actual annual return.

APY is different from APR (Annual Percentage Rate), which is used for loans and credit cards. APY is what you want to see on savings accounts, money market accounts, and certificates of deposit (CDs). APR is what you see on mortgages, car loans, and credit cards — and it works against you instead of for you.

Key Takeaways

  • APY includes the effect of compounding, so it shows the true amount you'll earn in a year, not just a simple percentage of your balance.
  • A higher APY means your money grows faster, so comparing APY between banks matters more than comparing the advertised interest rate alone.
  • APY changes over time — banks raise and lower rates based on Federal Reserve decisions and competition, so your earnings can go up or down.
  • Online banks typically offer higher APY than brick-and-mortar banks because they have lower overhead costs.

How compounding makes APY different from a simple interest rate

A simple interest rate tells you the percentage the bank will pay on your original deposit. If you put $1,000 in an account with 4% simple interest, you earn $40 per year, every year, on that $1,000.

Compounding changes that. Most banks compound interest daily or monthly, meaning they calculate how much you've earned so far, add it to your balance, and then calculate interest on the new, larger balance. If your account compounds daily at 4.50% APY, the bank divides that rate by 365, calculates your earnings for that day, adds it to your account, and repeats the next day on the new total. By the end of the year, you've earned interest on your interest.

APY captures that compounding mathematically and shows you the actual annual return. With $1,000 at 4.50% APY compounded daily, you earn about $46.13 instead of $45 — a small difference on a small balance, but the gap widens as your savings grow or as the APY increases.

Why APY varies between banks and accounts

Banks set their own APY rates based on how much they need to attract deposits and how much they can earn by lending that money out. Online banks — like Marcus, Ally, and American Express Personal Savings — typically offer higher APY than traditional banks because they don't pay for physical branches, tellers, or as much staff. That savings gets passed to you as a higher rate.

The Federal Reserve also influences APY. When the Fed raises its benchmark interest rate, banks tend to raise the APY they offer on savings accounts. When the Fed cuts rates, banks lower APY. This means your earnings can go up or down even if you do nothing — the rate your bank pays you changes based on broader economic conditions.

Different account types within the same bank also have different APY. A high-yield savings account pays more than a regular savings account. A CD (certificate of deposit) might pay more than either, but you have to lock your money away for a set period. Money market accounts sometimes pay more than savings accounts but may require a higher minimum balance.

How to compare APY between banks

When you're shopping for a savings account, look at the APY, not the interest rate. The APY is the number that matters for your actual earnings. Write down the APY for each account you're considering, along with any fees, minimum balance requirements, and how often interest compounds.

A 0.50% difference in APY sounds small, but on $10,000 it means $50 per year in extra earnings. On $100,000, it's $500 per year. Over five years, that gap compounds and grows. Use an online savings calculator to see the real difference between two accounts before you move your money.

Also check whether the APY is may provide or promotional. Some banks offer a higher rate for the first few months to attract new customers, then drop it to a lower rate. Read the fine print to see when the rate changes and what the standard APY will be after the promotional period ends.

What happens to your APY when rates change

Banks can change the APY they offer at any time, and they often do. If the Federal Reserve raises rates, your bank may raise your APY within days or weeks. If the Fed cuts rates, your bank may lower your APY just as quickly. You don't have to do anything — the new rate applies automatically to your account.

The exception is a CD. When you buy a CD, the APY is locked in for the entire term (three months, one year, five years, whatever you choose). If rates rise after you buy the CD, you're stuck with the lower rate. If rates fall, you're protected by the higher rate. That's the trade-off: you give up the ability to move your money, but you lock in a may provide return.

High-yield savings accounts have no such lock-in. Your APY can change at any time, which means your earnings can go up or down. This is why it's worth checking your account's APY every few months — if your bank's rate has fallen far behind competitors, you might move your money to a bank offering a higher APY.

The difference between APY and APR

APY and APR are not the same, and using them interchangeably will cost you money. APY is what you earn on savings. APR is what you pay on debt — mortgages, car loans, credit cards, and personal loans.

Both include compounding, but they work in opposite directions. A higher APY is better for you (your savings grow faster). A higher APR is worse for you (you pay more interest on what you owe). When you see APR on a credit card offer, that's the annual cost of borrowing. When you see APY on a savings account, that's the annual benefit of saving.

Frequently Asked Questions

Does APY mean I'll earn that exact amount?

No. APY shows the annual return if your balance stays the same and you don't make deposits or withdrawals. If you add money to your account, that new money earns less (because it hasn't been in the account for the full year). If you withdraw money, your total earnings are lower. APY is a rate, not a may provide of a specific dollar amount.

Is a higher APY always better?

Usually yes, but not if it comes with high fees or a minimum balance you can't meet. A 5.00% APY with a $25,000 minimum balance and a $10 monthly fee might earn you less than a 4.50% APY with no minimum and no fees, depending on your balance. Compare the full picture, not just the APY.

Can APY go negative?

In the United States, no. Banks will not pay you a negative APY on a savings account. However, if your account has fees that exceed your interest earnings, your net return (what you actually gain) can be negative. This is why checking for fees matters.

How often does the bank pay the interest shown in APY?

Banks compound and pay interest daily, monthly, or quarterly depending on the account. The APY already accounts for how often compounding happens, so you don't need to do the math yourself. The APY is the true annual return no matter the compounding frequency.

What if I withdraw my money before the year is up?

You still earn interest on the money you had in the account, calculated on a daily or monthly basis. The APY is an annual rate, but interest accrues continuously. If you withdraw after six months, you earn roughly half the annual APY (plus or minus, depending on the exact days and compounding schedule).