What determines how much interest you earn

The amount of interest you earn on a savings account depends on three things: the annual percentage yield (APY) the bank offers, how much money you keep in the account, and how long it stays there. A bank with a 4.5% APY will pay you more interest than one offering 0.01% APY on the same balance. The difference between these two is real money—on $10,000, that's $450 versus $1 per year.

Banks set their own APY rates based on what the Federal Reserve does with interest rates, how much competition exists in your area, and what type of account you have. A high-yield savings account at an online bank typically pays more than a traditional savings account at a brick-and-mortar bank. The bank's business model matters: online banks have lower overhead costs, so they pass some of that savings to you as higher rates.

Interest compounds, meaning you earn interest on your interest. If you have $10,000 at 4.5% APY and leave it untouched for a year, you earn $450. The next year, you earn interest on $10,450, not just the original $10,000. The longer your money sits, the more compounding works in your favor—though the effect is modest in savings accounts compared to longer-term investments.

Key Takeaways

  • Your interest earnings equal the APY rate multiplied by your account balance, so a 4.5% APY on $5,000 earns $225 per year.
  • Banks change their APY rates regularly in response to Federal Reserve decisions, so the rate you see today may be different in three months.
  • Online banks typically offer higher APY than traditional banks because they have fewer physical locations and lower operating costs.
  • Interest compounds daily or monthly depending on the bank, meaning you earn small amounts of interest on the interest you've already earned.
  • The difference between a 0.01% APY and a 4.5% APY on $50,000 is $2,500 per year, so comparing rates before opening an account matters.

How banks calculate your interest payment

Banks use a formula to calculate interest: your account balance multiplied by the APY, divided by the number of days in a year. If you have $20,000 at 4.5% APY, the calculation is ($20,000 × 0.045) ÷ 365 = $2.47 per day. Most banks compound this daily, meaning they add that $2.47 to your balance each day, and tomorrow's interest calculation includes today's interest.

The timing of deposits and withdrawals affects your total interest for the month. If you deposit $10,000 on the first day of the month, you earn interest on that full amount for all 30 days. If you deposit it on the 30th, you earn interest for only one day. Banks calculate interest based on your daily balance, so moving money in and out changes what you earn.

Some banks use a different method called "average daily balance," where they add up your balance at the end of each day and divide by the number of days in the month. This smooths out the effect of deposits and withdrawals. The difference between daily compounding and average daily balance is usually small—a few cents per month on typical balances—but it's worth checking your bank's terms if you move money frequently.

Why APY rates change and how often

Banks raise or lower their APY rates in response to decisions made by the Federal Reserve, which sets a target range for the federal funds rate. When the Fed raises rates, banks typically raise their savings account APY within days or weeks. When the Fed cuts rates, banks often cut their APY more slowly—sometimes taking months to pass the full cut to savers. This lag means you may earn less interest during a falling-rate environment.

Competition also drives rate changes. If a competitor bank launches a high-yield savings account at 5.0% APY and you're earning 3.5%, your bank may raise its rate to keep customers. During periods when many banks are competing for deposits, rates tend to be higher. During periods of low competition, rates drop even if the Fed hasn't moved.

You should check your bank's current APY once every few months, especially if you have a large balance. If your rate has dropped significantly and competitors are offering more, moving your money to a different bank takes about a week and costs nothing. Your existing account will close, and the new bank will transfer your balance electronically.

The difference between savings accounts and money market accounts

Money market accounts typically offer slightly higher APY than savings accounts, but they come with restrictions. Most money market accounts limit you to three to six withdrawals per month, while savings accounts have no withdrawal limit. If you need to access your money frequently, a savings account is more practical even if the rate is slightly lower.

Certificates of deposit (CDs) offer higher APY than both savings and money market accounts, but your money is locked in for a set period—usually three months to five years. If you withdraw early, you pay a penalty that can erase months of interest earnings. CDs make sense if you know you won't need the money for a specific length of time.

The trade-off is straightforward: higher APY usually means less access to your money or a longer commitment. For money you might need within the next year, a high-yield savings account strikes the best balance between rate and flexibility.

How to compare savings accounts and find the best rate

Start by listing the banks you're considering and writing down their current APY, minimum balance requirements, and any monthly fees. A bank offering 4.5% APY with a $25,000 minimum balance may not be better than one offering 4.2% with no minimum, depending on how much you have to deposit. Calculate the annual interest at each bank on your actual balance to see the real dollar difference.

Check whether the APY is may provide or promotional. Some banks offer a high rate for the first three months to attract new customers, then drop it to a lower rate. Read the fine print to see when the rate changes. A promotional rate that expires in 90 days is less valuable than a permanent rate that's 0.5% lower.

Verify that the bank is insured by the Federal Deposit Insurance Corporation (FDIC). FDIC insurance protects your deposits up to $250,000 per account type at each bank, so your money is safe even if the bank fails. All major banks carry FDIC insurance, but it's worth confirming before you move your money.

What happens to your interest if you withdraw money early

Withdrawing money from a savings account does not trigger a penalty—you can take out any amount at any time without losing interest. However, you stop earning interest on the money you withdraw. If you have $10,000 earning 4.5% APY and you withdraw $5,000, you now earn interest only on the remaining $5,000.

The timing of your withdrawal within a month can affect how much interest you receive that month. If you withdraw money on the 15th of the month, you earn interest on your full balance for the first 15 days, then on the reduced balance for the remaining days. Banks calculate this daily, so the effect is precise but usually small.

If you need to access your money regularly, a savings account is the right choice because there's no penalty. If you know you won't need the money for several months or years, a CD or money market account with a higher rate may be worth the restriction on withdrawals.

Frequently Asked Questions

How much interest will I earn on $5,000 in a savings account?

At a 4.5% APY, you earn $225 per year on $5,000. At a 0.5% APY, you earn $25 per year. The exact amount depends on your bank's current APY and whether interest compounds daily or monthly. Check your bank's website or call to find out the current rate.

Do I pay taxes on savings account interest?

Yes. Interest earned on a savings account is taxable income. Your bank will send you a Form 1099-INT at the end of the year showing how much interest you earned, and you report that amount on your tax return. The tax you owe depends on your overall income and tax bracket.

Can I lose money in a savings account?

No. Your principal balance is protected by FDIC insurance up to $250,000 per account type at each bank. You earn interest on top of what you deposit, so your balance only goes up (unless you make withdrawals). The only way to lose money is to withdraw more than you deposited.

Why is my bank's APY so much lower than the rate I see advertised online?

Your bank may have a lower rate because it's a traditional brick-and-mortar bank with higher operating costs, or because you opened your account years ago when rates were lower. Banks don't automatically raise rates on existing accounts when they raise rates for new customers. You can often get a higher rate by opening a new account at a different bank or asking your current bank to match a competitor's rate.

What's the difference between APY and APR?

APY (annual percentage yield) includes the effect of compounding, while APR (annual percentage rate) does not. For savings accounts, APY is the number that matters because it shows what you actually earn. APR is typically used for loans and credit cards, where it shows what you actually pay.