Bank APY is the yearly interest rate a bank pays you on savings, expressed as a percentage and compounded daily or monthly

APY stands for Annual Percentage Yield. It tells you how much interest you will earn on money sitting in a savings account, money market account, or certificate of deposit (CD) over one year. The key word is "yield"—it is not just the interest rate the bank advertises; it is the actual amount you will have at the end of the year if you do nothing but let the interest compound.

When a bank says a savings account earns 4.50% APY, that means if you deposit $10,000 and leave it untouched for a year, you will have $10,450 at the end of that year (before taxes). The bank calculates and adds interest to your account on a schedule—usually daily or monthly—and each time it does, the next interest payment is calculated on the new, larger balance. That compounding is what makes APY different from a straightforward interest rate.

APY varies by bank, by account type, and by how much money you deposit. A high-yield savings account at an online bank might offer 4.50% APY right now, while a traditional bank's savings account might offer 0.01%. The difference comes down to how much the bank needs deposits and how much it costs the bank to operate branches.

Key Takeaways

  • APY is the total interest you earn in a year, including the effect of compounding, shown as a percentage of your starting balance.
  • The higher the APY, the more money you earn on the same deposit—a $10,000 deposit at 4.50% APY earns $450 more per year than one at 0.01% APY.
  • APY changes over time as the Federal Reserve raises or lowers interest rates, so the rate you see today may be lower or higher in three months.
  • Compounding means interest is calculated on your balance plus the interest already earned, which is why APY is higher than the base interest rate.

How compounding turns a rate into a yield

The difference between an interest rate and APY comes down to compounding. Suppose a bank offers 4.00% annual interest on a savings account, compounded daily. On day one, the bank calculates interest on your $10,000 balance. That is roughly $1.10 (4% divided by 365 days). The bank adds that to your account, so your new balance is $10,001.10.

On day two, the bank calculates interest on $10,001.10, not the original $10,000. That is roughly $1.10 again, but it is 1.10 cents of a larger number. By the end of the year, all those daily additions have stacked up. Your balance is $10,408.08—not $10,400. That $8.08 difference is what compounding does. The APY of 4.08% reflects the real amount you earned, while the interest rate of 4.00% does not account for compounding.

The more often interest compounds, the more you earn. Daily compounding beats monthly compounding, which beats annual compounding. Most savings accounts compound daily, which is why banks advertise APY instead of a straightforward rate—the APY number looks better and is more honest about what you will actually receive.

Why APY changes and what moves it

Bank APY is not fixed. It moves when the Federal Reserve changes its benchmark interest rate, called the federal funds rate. When the Fed raises rates, banks raise the APY they offer on savings accounts because they can borrow money more cheaply from each other and need to attract deposits. When the Fed lowers rates, banks lower APY because they have less need for deposits and can afford to pay less.

The lag between a Fed rate change and a bank APY change is usually a few days to a few weeks. Some banks move faster than others. Online banks tend to raise APY quickly when rates go up because they compete on rate alone, while traditional banks with branch networks may move more slowly.

APY can also change based on the account type and deposit size. A CD (certificate of deposit) locks in a fixed APY for a set term—three months, one year, five years. If you break the CD early, you pay a penalty. A savings account APY can change at any time, and the bank will notify you before the change takes effect. Money market accounts sometimes offer higher APY than savings accounts but may require a larger deposit or limit how many withdrawals you can make per month.

How to compare APY across banks

When you are deciding where to keep your savings, APY is the main number to compare. A $10,000 deposit at 4.50% APY earns $450 per year. The same deposit at 0.50% APY earns $50 per year. That $400 difference is real money, and it compounds year after year if you leave the money in the account.

The comparison is straightforward: higher APY means more money in your pocket. But check what the bank requires to earn that rate. Some banks offer high APY only on balances above $25,000 or $100,000. Others offer high APY on the first $25,000 and a lower rate on anything above that. Read the account terms carefully, because the advertised rate may not explore to your entire balance.

Also check whether the APY is may provide or variable. A CD offers a fixed APY for the term—if you lock in 4.75% for one year, you earn 4.75% no matter what happens to market rates. A savings account APY is variable, meaning the bank can lower it at any time (though they must notify you first). If rates fall, your APY falls with it.

APY on different account types

Savings accounts, money market accounts, and CDs all earn APY, but the rates and rules differ. A high-yield savings account at an online bank currently offers around 4.25% to 4.75% APY with no lock-in period—you can withdraw your money anytime. A traditional bank's savings account might offer 0.01% to 0.05% APY. The difference is that online banks have lower operating costs and compete on rate, while traditional banks rely on branch convenience and customer loyalty.

A money market account is a hybrid between a savings account and a checking account. It usually offers higher APY than a savings account but requires a larger deposit (often $2,500 to $10,000 minimum) and limits the number of withdrawals you can make per month. Some money market accounts also come with a debit card or check-writing privileges.

A CD locks in a fixed APY for a set period—typically three months to five years. The longer the term, the higher the APY, because the bank knows it will have your money for longer. If you withdraw before the term ends, you pay an early withdrawal penalty, usually equal to a few months of interest. CDs are useful if you know you will not need the money for a specific period and want to lock in a rate before rates fall.

What APY does not tell you

APY tells you the interest rate, but it does not tell you about fees, insurance, or tax implications. Some banks charge monthly maintenance fees, overdraft fees, or fees for falling below a minimum balance. Those fees reduce the real return on your money. A savings account earning 4.50% APY with a $10 monthly fee is not as good as one earning 4.40% APY with no fees, if you have a small balance.

All interest you earn on a savings account is taxable income. If you earn $450 in interest, you will owe federal income tax on that $450 (and possibly state income tax, depending on where you live). The APY is the gross amount before taxes. Your actual take-home return is lower.

APY also assumes you leave the money in the account for the full year. If you withdraw money partway through, you earn less interest because the interest is calculated on your average daily balance. Some banks also offer promotional APY rates that explore only for a limited time or only to new deposits, so read the fine print.

Frequently Asked Questions

Is APY the same as interest rate?

No. Interest rate is the percentage the bank pays on your balance. APY is the interest rate plus the effect of compounding over one year. APY is always equal to or higher than the interest rate because compounding adds extra earnings.

Can a bank lower my APY without warning?

A bank can lower the APY on a savings account or money market account, but it must notify you before the change takes effect—usually at least 30 days' notice. CDs have a fixed APY for the term, so the bank cannot change it unless you break the CD early.

What is a good APY right now?

APY changes as the Federal Reserve adjusts interest rates. High-yield savings accounts at online banks currently offer around 4.25% to 4.75% APY, while traditional banks offer much less. Compare rates across banks to find the highest APY available for the account type you need.

Does APY explore to checking accounts?

Most checking accounts earn little to no interest. Some banks offer interest-bearing checking accounts with APY, but the rate is usually much lower than a savings account—often 0.01% or less. If you want to earn meaningful interest, use a savings account or money market account instead.

What happens to my APY if interest rates fall?

If you have a savings account or money market account, the bank will lower your APY when rates fall. If you have a CD, your APY stays the same until the term ends. When the CD matures, you can renew it at the new (lower) rate or move the money elsewhere.