What a savings account interest rate is

A savings account interest rate is the percentage of your balance that a bank pays you each year for letting them hold your money. If you deposit $1,000 and the bank offers a 4.5% annual rate, the bank calculates how much interest you earn based on that percentage and adds it to your account over time.

The bank pays you interest because they use your deposits to lend money to other customers—mortgages, car loans, business loans. They keep the difference between what they pay you and what they charge borrowers. The interest rate is their offer: this is what we'll pay you to keep your money here instead of somewhere else.

Interest rates on savings accounts change. Banks set their own rates and adjust them based on what the Federal Reserve does with its benchmark rate. When the Fed raises rates, banks typically raise savings rates. When the Fed lowers rates, savings rates usually fall too. This means the rate you see today may not be the rate you earn six months from now.

Key Takeaways

  • Interest rates are expressed as an annual percentage, but most banks calculate and add interest to your account monthly or daily.
  • The actual amount you earn depends on three things: the rate itself, how much money you have in the account, and how long it stays there.
  • Banks can change rates whenever they want, so a high rate today does not mean you will earn that rate forever.
  • High-yield savings accounts at online banks typically pay more than traditional savings accounts at brick-and-mortar banks.
  • The rate you see advertised is usually the APY (annual percentage yield), which includes the effect of compounding—interest earning interest.

How banks calculate what you earn

Banks use one of two methods to calculate interest: simple interest or compound interest. With simple interest, the bank pays you a percentage of your original deposit only. With compound interest—which is what most savings accounts use—the bank pays you interest on your deposit plus interest on the interest you already earned.

Here is a concrete example. Say you deposit $10,000 in an account earning 4% APY, compounded monthly. The bank divides the annual rate by 12 to get a monthly rate of about 0.33%. In month one, you earn roughly $33. In month two, you earn 0.33% of $10,033 (your original deposit plus the interest from month one), which is about $33.11. The difference is small at first, but it grows over time. After one year, you would have earned about $408 instead of exactly $400.

The advertised rate is usually the APY (annual percentage yield), not the APR (annual percentage rate). APY includes the effect of compounding, so it tells you the real amount you will earn if you leave the money untouched for a year. APR does not include compounding, so it would understate what you actually get.

Why rates differ between banks

Different banks offer different rates because they have different costs and different business models. An online bank with no physical branches has lower overhead than a bank with hundreds of locations, so it can afford to pay you more. A bank that is trying to attract new customers might offer a higher rate temporarily. A bank that already has plenty of deposits might lower its rate because it does not need more money coming in.

The type of account also matters. A regular savings account typically earns less than a money market account, which typically earns less than a certificate of deposit (CD). The tradeoff is access: with a savings account, you can withdraw money whenever you want. With a CD, you lock your money away for a set period (three months, one year, five years) and pay a penalty if you take it out early. The bank pays you more for that restriction because it knows exactly how long it will have your money.

Your balance can matter too. Some banks offer tiered rates—a higher rate if you maintain a larger balance. Others offer the same rate to everyone. A few banks offer promotional rates for new customers that expire after a few months, then drop to a lower standard rate.

APY versus APR: which one matters

When you are comparing savings accounts, always look at the APY, not the APR. APY is the annual percentage yield—the real return you will get after compounding is factored in. APR is the annual percentage rate before compounding, and it will always be lower than the APY for the same account.

Banks are required to display the APY prominently when they advertise a rate, so you should see it clearly on their website or in their marketing materials. If you see only an APR or an interest rate without the "Y" or the "R" label, ask the bank which one it is before you open an account.

The difference between APY and APR is usually small for savings accounts—often less than 0.1%—but it adds up over time, especially if you have a large balance. On a $100,000 deposit, the difference between a 4.0% APR and a 4.08% APY could mean an extra $80 per year in your pocket.

How often interest is added to your account

Banks calculate interest daily, monthly, quarterly, or annually depending on the account. Most savings accounts calculate daily and add the interest monthly, though some add it quarterly or annually. The more frequently interest is added, the more you benefit from compounding, because you start earning interest on that interest sooner.

Daily calculation with monthly crediting is the most common setup. The bank looks at your balance every day, calculates how much interest you earned that day, and keeps a running total. At the end of the month, it deposits the full month's interest into your account all at once. Some banks credit interest on the first day of the month; others do it on the last day or on a specific date.

This matters if you are moving money in and out frequently. If you deposit $5,000 on the 15th and withdraw it on the 20th, you will earn interest only for those five days, not for the full month. Banks calculate this based on the daily balance method, so you earn interest only on the money that was actually in the account.

What happens when rates change

Banks can change savings account rates at any time without notifying you in advance. They are not required to give you notice, though many do send an email or a letter. The new rate applies to interest earned going forward, not to money you already have in the account.

If rates go up, your bank may or may not raise your rate. If rates go down, your bank will almost certainly lower your rate. This is why it makes sense to shop around periodically. If you opened a savings account two years ago when rates were lower, you might be earning significantly less than what new accounts are offering today.

If your bank lowers your rate and you are unhappy, you can move your money to a different bank. There is no penalty for closing a savings account and opening one elsewhere. The only cost is the time it takes to set up the transfer and update any automatic deposits or payments.

How to find the best rate for your situation

The highest rate is not always the best choice if it comes with restrictions you cannot live with. A CD might pay 5% but lock your money away for two years. A money market account might require a $25,000 minimum balance. A promotional rate might drop to 1% after six months. Read the fine print before you decide.

For money you need to access regularly, a high-yield savings account is usually the best fit. These accounts typically offer rates competitive with CDs but let you withdraw money whenever you want. For money you will not need for a specific period, a CD ladder—opening multiple CDs with different maturity dates—can lock in higher rates while giving you access to some of your money at regular intervals.

Compare rates across at least three banks before opening an account. Online banks, credit unions, and traditional banks all offer savings accounts, and their rates can vary significantly. A site that aggregates current rates can give you a starting point, but always verify the rate on the bank's own website before you open an account, because rates change frequently.

Frequently Asked Questions

Does my interest rate stay the same forever?

No. Banks can change rates whenever they want. Most rates move when the Federal Reserve changes its benchmark rate, but banks can also adjust rates based on their own business needs. Check your bank's website or your account statements periodically to see if your rate has changed.

Why is my savings account earning almost no interest?

Traditional savings accounts at brick-and-mortar banks often pay very low rates—sometimes 0.01% or less. Online banks and credit unions typically pay much more. If your bank is paying less than 3%, you may be able to earn significantly more by moving your money to a different institution.

What is the difference between a savings account and a money market account?

Money market accounts usually pay higher interest than savings accounts but often require a larger minimum balance and limit how many withdrawals you can make per month. Savings accounts are more flexible but typically pay less. Both are FDIC-insured up to $250,000 if held at a bank.

Can I lose money in a savings account?

No, not from the bank's perspective. Your balance will not go down because of the interest rate. However, inflation can reduce what your money can buy. If inflation is 3% and your savings account earns 2%, you are losing purchasing power even though your account balance is growing.

How much interest will I earn on $10,000?

It depends on the rate and how long the money stays in the account. At 4% APY, $10,000 earns about $400 in one year. At 5% APY, it earns about $500. The exact amount also depends on how often interest is compounded and whether you add or withdraw money during the year.