Interest is paid by the bank from its own earnings, deposited into your account on a schedule you can see

Banks pay interest on savings accounts because they lend out the money you deposit to other customers—mortgages, car loans, business lines of credit. The bank keeps the difference between what it pays you and what it charges borrowers. That difference is their profit. Your interest payment is a small share of that profit, calculated as a percentage of your balance and added to your account on a regular schedule: daily, monthly, or quarterly, depending on the bank's terms.

The amount you earn depends on three things: your account balance, the interest rate the bank offers, and how often interest compounds (meaning interest earned on top of previous interest). A bank might advertise a rate of 4.50% annual percentage yield, or APY. That rate is what you'd earn if your balance stayed the same for a full year and the bank paid interest once at the end. In reality, most banks calculate and deposit interest more frequently, which means you earn a tiny bit of interest on your interest.

You can watch interest arrive in your account. Log into your bank's website or app and look at your transaction history. You'll see deposits labeled "interest paid" or "interest credit" on the dates the bank processes them. The amount will be small—usually a few cents to a few dollars per month on a typical savings account—but it's real money that belongs to you.

Key Takeaways

  • Banks pay interest from the money they earn by lending out your deposits to other customers.
  • Your interest rate is shown as an annual percentage yield (APY), but most banks calculate and deposit interest monthly or quarterly.
  • Interest compounds when banks pay interest on the interest you've already earned, which increases your total earnings over time.
  • You can see interest payments in your account history as deposits labeled "interest paid" or "interest credit."
  • Higher APY rates mean more interest income, so comparing rates between banks before opening an account matters.

How the interest rate is set and why it changes

Banks set their own interest rates, but they don't choose them in a vacuum. The Federal Reserve sets a target range for the federal funds rate—the rate at which banks lend to each other overnight. When the Fed raises or lowers that rate, banks adjust the rates they offer to customers. A higher Fed rate usually means banks will offer higher APY on savings accounts because they're earning more from lending. A lower Fed rate usually means lower APY.

Your specific rate depends on the type of account and the bank. A high-yield savings account at an online bank might offer 4.50% APY, while a traditional savings account at a brick-and-mortar bank might offer 0.01% APY. The difference is real and compounds over time. On a $10,000 balance, 4.50% APY earns roughly $450 per year, while 0.01% APY earns about $1 per year. Banks with lower overhead costs (online banks) can afford to pay higher rates and still profit.

Rates change frequently. A bank might offer 4.50% one month and lower it to 4.25% the next, especially if the Fed signals it will cut rates. Your existing balance usually keeps earning at the old rate until the bank formally changes your account terms, but new deposits and any renewal of promotional rates will use the new rate. Check your bank's website or call to confirm the current rate on your specific account.

How compounding multiplies your earnings

Compounding is when interest is calculated not just on your original deposit, but on the interest you've already earned. If you deposit $1,000 at 4.00% APY and the bank compounds monthly, you earn about $3.33 in the first month. In the second month, you earn interest on $1,003.33, not just $1,000. The difference is tiny at first, but it grows. Over a year, that $1,000 becomes $1,040.81 instead of $1,040.00—an extra 81 cents from compounding alone.

The more frequently a bank compounds, the more you earn. Daily compounding beats monthly compounding, which beats quarterly compounding. Most online banks compound daily, which is why they often advertise higher effective earnings than banks that compound quarterly. The difference is small on a savings account, but it's real. Over five years on a $10,000 balance at 4.00% APY, daily compounding earns about $2,214 total, while quarterly compounding earns about $2,201—a $13 difference.

You don't have to do anything to get compounding. It happens automatically. The bank's system calculates interest on your current balance (including previous interest) and deposits the new interest on the schedule stated in your account agreement. You just watch your balance grow.

When interest is calculated and when it hits your account

Banks calculate interest daily on most savings accounts, but they deposit it on different schedules. Some deposit monthly, some quarterly, some annually. The account agreement or the bank's website will state the deposit frequency. When you open an account, ask or look for a document called the "Truth in Savings" disclosure—it lists the APY, the compounding frequency, and the deposit frequency.

The timing matters if you're trying to move money or close an account. If your bank deposits interest quarterly and you close the account in month two of a quarter, you won't receive the interest earned in months one and two until the next deposit date—or you might forfeit it entirely. Some banks pay accrued interest when you close an account; others don't. Read the fine print or call before closing.

Interest is not paid on money you withdraw. If you have $5,000 on January 1 and withdraw $2,000 on January 15, the bank calculates interest only on the days you held the full $5,000 and the days you held $3,000. Some accounts penalize you for withdrawals by lowering your rate or charging a fee. High-yield savings accounts typically allow six withdrawals per month without penalty, but confirm your account's rules before opening.

How to compare interest rates between banks

The APY is the only number that matters when comparing accounts. Ignore the interest rate percentage if it's listed separately—use APY, which includes the effect of compounding. A bank advertising 4.48% rate with daily compounding might have a 4.50% APY. Another bank advertising 4.50% rate with quarterly compounding might have a 4.49% APY. The APY tells you what you'll actually earn.

Check the APY on the bank's website, but verify it's current. Rates change frequently, and a website might not update when ready. Call the bank or use a rate-comparison tool like Bankrate or DepositAccounts to see current rates across multiple banks. Write down the APY, the compounding frequency, the deposit frequency, and any fees or withdrawal limits. A slightly higher APY at a bank with a $25 monthly fee might earn you less than a slightly lower APY at a bank with no fees.

Consider the bank's stability and your access to your money. A bank insured by the Federal Deposit Insurance Corporation (FDIC) protects your deposits up to $250,000 if the bank fails. Online banks are FDIC-insured just like brick-and-mortar banks. If you need to access your money quickly, make sure the bank offers online transfers or a debit card. Some high-yield savings accounts limit you to transfers by phone or mail, which takes longer.

What happens to interest if you withdraw money early

Interest accrues (builds up) every day based on your balance that day. If you withdraw money, you stop earning interest on that amount when ready. If you have $5,000 earning 4.50% APY and withdraw $2,000, you now earn 4.50% only on the remaining $3,000. The interest you already earned stays in your account—you don't lose it. But future interest is calculated on the lower balance.

Some savings accounts have penalties for early withdrawal, though these are less common now. A certificate of deposit (CD) is different from a savings account and usually charges a penalty if you withdraw before the maturity date. A regular savings account should not penalize you for withdrawals, but some accounts limit the number of free withdrawals per month. After that limit, you might pay a fee per withdrawal. Check your account agreement.

If you're saving toward a goal and want to avoid the temptation to withdraw, consider a CD instead of a savings account. A CD locks your money away for a set term (three months, one year, five years) and usually offers a higher APY than a savings account. You can't withdraw without a penalty, so you're forced to leave the money alone and let interest compound. When the term ends, the bank returns your principal plus all interest earned.

Tax treatment of savings account interest

Interest you earn on a savings account is taxable income. The bank will send you a Form 1099-INT at the end of the year if you earned $10 or more in interest. You report this income on your federal tax return. The tax rate depends on your overall income and tax bracket. If you earned $500 in interest and you're in the 22% tax bracket, you'll owe roughly $110 in federal tax on that interest (plus any state or local tax).

This is why the real return on your savings is less than the APY. If you earn 4.50% APY on $10,000 and owe 22% tax on the $450 interest, your after-tax return is about 3.51%. This matters more when interest rates are high. In a low-rate environment, the tax impact is smaller because you're earning less interest overall.

Some accounts offer tax advantages. A savings account held in an Individual Retirement Account (IRA) or a Health Savings Account (HSA) grows tax-free or tax-deferred, meaning you don't pay tax on the interest until you withdraw (or never, depending on the account type). If you have money you won't need for retirement, a tax-advantaged account can be a better place for savings than a regular taxable savings account.

Frequently Asked Questions

How often should I check my account to see if interest was deposited?

Check whenever you want—it won't change the deposit schedule. Most banks deposit interest monthly or quarterly on a set date. You can see the exact date in your account agreement or by calling the bank. Once you know the date, you only need to check around that time to confirm the deposit arrived.

Can I lose money in a savings account if interest rates drop?

No. Your principal (the money you deposited) is always yours. If interest rates drop, you'll earn less interest going forward, but you won't lose the money you put in or the interest you've already earned. The only way to lose money is if the bank fails and your balance exceeds the FDIC insurance limit of $250,000.

Why do online banks pay higher interest than traditional banks?

Online banks have lower overhead costs—no physical branches, fewer employees, lower rent. They pass those savings to customers by offering higher APY. A traditional bank with hundreds of branches has to pay for all that infrastructure, so it can't afford to pay as much interest and still profit.

What's the difference between APY and APR on a savings account?

APY (annual percentage yield) includes compounding and shows what you'll actually earn. APR (annual percentage rate) does not include compounding and is rarely used for savings accounts. Always use APY when comparing savings accounts. APR is used for loans and credit cards.

If I move my money to a different bank, do I lose the interest I earned?

No. Interest you've already earned is yours to keep. When you transfer money to a new bank, the old bank deposits any accrued interest into your account before or after the transfer, depending on the bank's policy. Confirm with both banks what happens to accrued interest before you move your money.