Interest accrues on a daily basis, but you only see the money added to your account on a schedule set by your bank

Interest on a savings account is calculated using the balance in your account and the annual percentage yield (APY) your bank offers. Most banks calculate interest daily — they take your account balance at the end of each day, multiply it by the daily interest rate, and add that tiny amount to a running total. That running total is called accrued interest. Even though interest accrues every single day, your bank does not deposit it into your account every day. Instead, they deposit the accrued interest on a schedule: monthly, quarterly, or annually, depending on the bank's terms.

The key difference between the interest rate and the APY matters here. The interest rate is the percentage your bank pays on your money for one year. The APY is what you actually earn when interest compounds — when the interest you earn starts earning interest itself. If your bank compounds interest monthly, your APY will be slightly higher than the stated rate because you are earning interest on interest. A bank advertising a 4.50% APY is telling you the real number: that is what you will earn in a year if you leave the money untouched.

Key Takeaways

  • Interest accrues daily at most banks, meaning a small amount is calculated and added to your running total every day based on your current balance.
  • The APY is the real number to compare between banks because it includes the effect of compounding — interest earning interest.
  • Your bank deposits accrued interest into your account on a set schedule (usually monthly or quarterly), not daily.
  • A higher balance means more interest accrues each day, so moving money into savings earlier in the month generates more total interest than waiting until the end of the month.

How daily accrual works in practice

Suppose you have $10,000 in a savings account with a 4.00% APY, and your bank compounds interest daily. The bank converts that annual rate to a daily rate by dividing by 365 (or sometimes 360, depending on the bank). At 4.00% APY, the daily rate is roughly 0.01096%. On a $10,000 balance, that means about $1.10 accrues on that single day. The next day, if your balance is still $10,000, another $1.10 accrues. Over a month, roughly $33 accrues. Over a year, roughly $400 accrues — which matches the 4.00% APY.

The moment you withdraw money, the daily accrual amount drops. If you withdraw $5,000, the next day's accrual is calculated on the remaining $5,000, not the original $10,000. If you deposit money, the accrual amount increases starting the next day. This is why the timing of deposits and withdrawals matters: money sitting in the account for the full month generates more interest than money that arrives on the 25th.

Some banks use a different method called the average daily balance. Instead of calculating interest on the balance at the end of each day, they add up all your daily balances for the month and divide by the number of days. Then they apply the monthly interest rate to that average. The result is usually very similar to daily compounding, but the calculation method is different.

When interest actually lands in your account

Accrued interest sits in a calculation until your bank's deposit schedule arrives. Most banks deposit interest monthly — on the first day of the month, or on a date set in your account agreement. Some deposit quarterly (every three months), and a few still deposit annually. When the deposit date arrives, all the accrued interest from the previous period is added to your account balance at once. You can see this transaction in your account history, usually labeled "Interest Paid" or "Interest Deposit."

The day after interest deposits, the accrual process starts over from zero. Your new balance is higher, so the next day's accrual is calculated on that higher amount. This is where compounding creates a real difference over time. If you earn $33 in interest one month and do not withdraw it, the next month you earn interest on $10,033, not just $10,000. The extra $33 earns a tiny bit of interest itself.

Why APY matters more than the stated rate

Banks are required to disclose the APY, and that is the number you should use to compare accounts. The APY already includes the effect of compounding at that bank's frequency. A bank offering 4.50% APY with daily compounding will pay you more over a year than a bank offering 4.50% with annual compounding, even though both say 4.50%. The APY accounts for that difference.

If a bank advertises only an interest rate without an APY, that is a red flag. The APY is the real earning number. When you are comparing savings accounts, line up the APYs side by side. A 4.75% APY at one bank beats a 4.50% APY at another bank, and the difference compounds over years. On $10,000, that 0.25% difference is $25 per year — small, but real.

How balance changes affect your interest

Interest accrues on whatever balance you have on any given day. If you start the month with $10,000 and add $5,000 on day 15, the first 14 days accrue interest on $10,000, and days 15 through the end of the month accrue interest on $15,000. The total interest for the month is higher than if you had kept $10,000 the whole time, because half the month earned interest on a larger balance.

Conversely, if you withdraw money mid-month, the accrual drops immediately. Withdrawing $5,000 on day 15 means the second half of the month earns interest on a smaller balance. The interest you already accrued in the first 14 days stays accrued and will be deposited on the interest deposit date, but future accrual is lower.

This is why some people move money into savings as early in the month as possible: every extra day the money sits in the account, it is accruing interest. The difference is small on small balances, but on $50,000 or more, moving money a week earlier can mean an extra dollar or two in interest over the year.

What happens if you close the account before interest deposits

If you close a savings account before the interest deposit date, you receive the accrued interest up to the day you close. Banks are required to pay you all interest that has accrued, even if the regular deposit schedule has not arrived yet. When you close the account, the bank calculates interest through the closing date and adds it to your final balance. You receive that total when the account closes.

The one exception is if you close the account on a day when the bank has already calculated interest for that day. Some banks calculate interest at the end of the business day, so if you close in the morning, you might not receive that day's accrual. Check with your bank about the exact timing if you are closing an account and want to know the precise final balance.

Frequently Asked Questions

Does interest accrue on money I just deposited?

Yes, but usually starting the next business day. Most banks begin accruing interest on deposits the day after they are posted to your account. If you deposit money on a Friday, accrual typically starts on Monday. Check your account agreement for the exact timing at your bank.

What if my bank changes the APY?

Banks can change the APY at any time, and they are required to notify you before the change takes effect. The new rate applies to interest accruing after the change date. Interest that already accrued at the old rate is not recalculated. If rates drop, your future accrual is lower; if rates rise, your future accrual is higher.

Can I earn interest on interest before the deposit date?

No. Interest compounds only after it is actually deposited into your account. Accrued interest sitting in the bank's calculation does not earn interest itself until the deposit date arrives and it becomes part of your balance. After that, the new higher balance generates more accrual each day.

Why do some banks compound interest more often than others?

Banks choose their compounding frequency as part of their account terms. Daily compounding is more common now and pays slightly more than monthly or quarterly compounding. The difference is small on most balances, but the APY already reflects the compounding frequency, so you can compare accounts fairly by looking at APY alone.

Does a higher balance mean I earn more interest?

Yes. A larger balance generates a larger daily accrual amount. On a $50,000 balance at 4.00% APY, you earn roughly $2,000 per year. On a $10,000 balance at the same rate, you earn roughly $400 per year. The percentage is the same, but the dollar amount scales with your balance.