What determines your savings account interest
The amount you earn depends on three things: how much money you keep in the account, the annual percentage yield (APY) the bank offers, and how long the money stays there. A bank with a 4.5% APY will pay you more than one offering 0.01% APY on the same balance—but only if you compare them at the same time, because rates change.
Banks set their own rates based on what the Federal Reserve does with its benchmark rate. When the Fed raises rates, some banks raise their savings rates within days. When the Fed cuts rates, banks often cut savings rates more slowly. Online banks typically offer higher rates than brick-and-mortar banks because they have lower overhead costs.
The math is straightforward: multiply your account balance by the APY, then divide by 12 to get your monthly interest. A $10,000 balance at 4.5% APY earns about $37.50 per month (before any fees reduce it). At 0.01% APY, the same $10,000 earns about $0.08 per month.
Key Takeaways
- Your interest earnings equal your balance multiplied by the APY rate, divided by 12 for a monthly figure, though the actual deposit schedule affects the final amount.
- APY rates vary widely between banks—currently ranging from under 0.01% at some traditional banks to over 5% at online banks—and change when the Federal Reserve adjusts its benchmark rate.
- Interest compounds daily at most banks, meaning you earn interest on interest, but the difference between daily and monthly compounding is usually less than a dollar per year on typical balances.
- Keeping money in a savings account for longer earns more total interest, but moving to a higher-rate account mid-year can increase your annual earnings even if you started the year elsewhere.
How compounding affects what you earn
Most savings accounts compound interest daily, which means the bank calculates interest on your balance each day, adds it to your account, and then calculates the next day's interest on the new total. This creates a small snowball effect: you earn interest on the interest you already earned.
The difference between daily and monthly compounding is small on typical balances. On $10,000 at 4.5% APY, daily compounding earns you roughly $0.50 more per year than monthly compounding. On $100,000, the difference is about $5 per year. The real difference comes from how long your money stays in the account and whether you add to it regularly.
If you deposit $500 per month into a savings account at 4.5% APY, you will earn more total interest than if you deposited $6,000 once at the start of the year, because the monthly deposits spend more time in the account earning interest. A savings calculator that accounts for your deposit schedule will show you a more accurate picture than the straightforward formula.
How to compare rates across banks
Check the APY, not the interest rate—APY already includes the effect of compounding, so it is the true number to compare. A bank advertising "4.5% interest rate compounded daily" is showing you the APY. A bank showing only "4.4% interest rate" without mentioning compounding is hiding information.
Look at the current APY on the bank's website or a rate-tracking site like Bankrate or DepositAccounts. Rates change frequently, so a rate you saw last month may no longer be current. Most banks display the APY prominently on the savings account product page.
Also check the minimum balance requirement and any monthly fees. A 5% APY account with a $25 monthly fee costs you $300 per year, which wipes out the interest on a $6,000 balance. Some banks waive fees if you maintain a minimum balance or set up direct deposit.
When interest rates rise or fall
When the Federal Reserve raises its benchmark rate, online banks typically raise savings rates within one to three days. Traditional banks often wait longer or raise rates by a smaller amount. If you are in a low-rate account when the Fed raises rates, moving your money to a higher-rate bank can increase your annual earnings by hundreds of dollars on a large balance.
When the Fed cuts rates, banks cut savings rates more slowly and sometimes by smaller amounts than the Fed's cut. This means the gap between online and traditional bank rates often widens after a Fed rate cut. Switching accounts becomes less urgent because the rate advantage shrinks.
You can move money between banks without penalty—there is no "lock-in" period on savings accounts like there is on certificates of deposit. If you find a bank offering a significantly higher rate, you can transfer your balance in three to five business days.
How fees reduce your interest earnings
A monthly maintenance fee, overdraft fee, or low-balance fee directly reduces what you keep from your interest. If you earn $5 per month in interest but pay a $5 monthly fee, you break even. If the fee is $10, you lose money.
Most online banks charge no monthly fees and have no minimum balance requirements. Many traditional banks charge $5 to $15 per month unless you maintain a certain balance or set up direct deposit. Read the fee schedule on the account details page before opening an account.
Some banks charge a fee if your balance drops below a threshold for even one day during the month. Others waive the fee if you maintain the minimum only on the last day of the month. The specific rules matter when you are deciding whether the higher APY is worth the fee risk.
Real examples of what different balances earn
| Balance | APY 0.01% | APY 1.5% | APY 4.5% | APY 5.35% |
|---|---|---|---|---|
| $1,000 | $0.10/year | $15/year | $45/year | $53.50/year |
| $10,000 | $1/year | $150/year | $450/year | $535/year |
| $50,000 | $5/year | $750/year | $2,250/year | $2,675/year |
| $100,000 | $10/year | $1,500/year | $4,500/year | $5,350/year |
These figures assume the balance stays constant for the full year and no fees are charged. If you add money monthly or withdraw regularly, your actual interest will differ. The difference between a 4.5% account and a 5.35% account on a $50,000 balance is $425 per year—enough to notice.
The table shows why the bank you choose matters more than the balance itself. Moving $50,000 from a 0.01% account to a 5.35% account increases your annual earnings from $5 to $2,675—a difference of $2,670 per year. That same move with a $10,000 balance increases earnings from $1 to $535, still a meaningful difference.
Frequently Asked Questions
Do I have to pay taxes on savings account interest?
Yes. Interest earned in a savings account is taxable income. Banks send you a 1099-INT form at the end of the year if you earned $10 or more in interest. You report this on your tax return. The interest is taxed at your ordinary income tax rate, not at a special rate.
Can I move my money to a different bank without losing interest?
Yes. Transferring money between banks does not reset your interest or cause you to lose earnings. Interest accrues daily, so you earn interest right up until the money leaves one bank and continues earning at the new bank once it arrives. The transfer itself takes three to five business days.
What happens to my interest if I withdraw money mid-month?
Most banks calculate interest based on your daily balance, so withdrawing money reduces the balance on which interest is calculated for the remaining days of the month. If you withdraw $5,000 on the 15th of a 30-day month, you earn interest on the full balance for 14 days and the reduced balance for 16 days.
Is there a maximum amount I can earn in interest per year?
No. There is no limit on how much interest you can earn in a savings account. The limit is on how much the FDIC insures if the bank fails—currently $250,000 per depositor per bank. You can earn interest on balances above that, but only the first $250,000 is protected if the bank closes.