What you earn depends on the bank's rate and how much you have saved
The amount of interest you earn from a savings account is determined by two things: the annual percentage yield (APY) the bank offers and your account balance. A bank paying 4.50% APY on $10,000 will pay you roughly $450 per year, while the same rate on $1,000 pays about $45. The interest compounds—meaning you earn interest on your interest—so your balance grows slightly faster each month, but the effect is small on typical savings account balances.
Interest rates vary widely. As of early 2024, online banks typically offer between 4.00% and 5.35% APY on savings accounts, while traditional brick-and-mortar banks often pay 0.01% to 0.50%. The difference matters: at 4.50% APY, $10,000 grows to $10,450 in one year; at 0.01%, it grows to $10,001. Banks set their own rates based on what the Federal Reserve charges them to borrow money, competition for deposits, and their operating costs.
Key Takeaways
- Your interest earnings equal your account balance multiplied by the APY, divided by 12 for a monthly estimate, though the exact amount depends on how often the bank compounds interest.
- Online banks typically pay 4 to 5 times more interest than traditional banks because they have lower overhead costs.
- Interest rates change over time—a rate advertised today may be lower next month, and banks can lower rates without notice.
- The interest you earn is taxable income; you will receive a 1099-INT form from your bank if you earn $10 or more in a calendar year.
How banks calculate and pay your interest
Banks use your daily balance to calculate interest, though the exact method varies. Most savings accounts compound interest daily, meaning the bank calculates what you owe based on your balance each day, then adds that tiny amount to your account. At the end of each month or quarter, the bank deposits the total interest earned into your account.
The formula is straightforward: (Balance × APY) ÷ 365 = daily interest. If you have $10,000 and the APY is 4.50%, you earn about $1.23 per day. Over 30 days, that is roughly $36.99. The actual amount varies slightly depending on whether the bank uses 360 or 365 days in its calculation, and whether your balance changed during the month.
Some banks pay interest monthly, others quarterly. This timing does not change your annual earnings—you still get the full APY—but it affects when you see the money in your account. A few banks still use "simple interest," which does not compound, but this is rare for savings accounts.
Why rates differ so much between banks
Online banks pay more because they do not operate physical branches. They have no tellers, no rent on storefronts, and no staff in dozens of locations. That lower cost means they can afford to pay you more of what they earn from lending your deposits to other customers. A bank like Marcus or Ally can offer 4.50% APY; a regional bank with 50 branches cannot compete at that rate without losing money.
Banks also compete for deposits. When the Federal Reserve raises its benchmark rate, online banks raise their savings rates quickly to attract new customers. Traditional banks raise rates more slowly because they rely on existing customers who do not shop around. If you have been with the same bank for years and have not checked rates elsewhere, you are almost certainly earning far less than you could.
Some banks offer promotional rates—a higher APY for the first few months—to bring in new customers. These rates usually drop after the promotional period ends, so read the fine print before opening an account.
How inflation affects what your interest actually buys
Interest earnings matter less when inflation is high. If you earn 4.50% APY but inflation is 3.50%, your money's real purchasing power only grows by about 1% per year. If inflation is 5%, you are actually losing purchasing power even though your account balance is growing. This is why it matters to shop for the highest rate available—the difference between 4.50% and 0.50% is enormous when inflation is factored in.
You cannot control inflation, but you can control which bank holds your money. Moving $10,000 from a 0.01% account to a 4.50% account means an extra $450 per year in your pocket—money that stays yours and does not go to the bank.
Interest rates change, and banks can lower yours
The rate you see advertised today is not locked in for life. Banks can lower rates at any time without notice, though they must notify you before the change takes effect. When the Federal Reserve cuts its benchmark rate, online banks typically lower their savings rates within days. When the Fed raises rates, online banks raise theirs quickly too, but traditional banks often lag behind.
If you lock in a high rate at an online bank today, that rate will likely drop within months or a year. This does not mean you should avoid online banks—you should instead plan to check rates every few months and move your money if a better rate appears elsewhere. Most online savings accounts have no fees and no minimum balance, so switching is free and takes a few days.
Tax on interest earnings
Interest you earn is taxable income. The bank reports it to the IRS on a 1099-INT form, which you receive if you earned $10 or more in a calendar year. You must report this income on your tax return, and it is taxed at your ordinary income tax rate—not at a lower capital gains rate.
If you earn $450 in interest and you are in the 22% tax bracket, you owe about $99 in federal taxes on that interest. Some states also tax interest income. This does not change how much interest the bank pays you, but it does reduce what you keep. A 4.50% APY becomes roughly 3.51% after federal taxes if you are in the 22% bracket.
Comparing savings accounts to other places for your money
Savings accounts are not the only place to earn interest. Money market accounts often pay the same rate as savings accounts but allow you to write checks. Certificates of deposit (CDs) typically pay higher rates—sometimes 5.00% or more—but lock your money away for a set period (three months to five years). High-yield savings accounts are simply savings accounts at online banks; the term just means they pay more than traditional banks.
If you need access to your money within a few months, a high-yield savings account makes sense. If you know you will not touch the money for a year or more, a CD usually pays more. If you need to write checks against your savings, a money market account is an option, though rates are usually the same as savings accounts.
Frequently Asked Questions
How often does interest get added to my account?
Most banks add interest monthly or quarterly, though interest compounds daily. You will see the total in your account on the bank's stated schedule—usually the last day of the month or quarter. The timing does not affect your annual earnings; you still receive the full APY regardless of whether interest posts monthly or quarterly.
Can I lose money in a savings account?
No. Your principal is protected by FDIC insurance up to $250,000 per bank. You cannot lose your deposit, though inflation can reduce its purchasing power. Interest earnings are never may provide—the bank can lower rates—but your original balance is safe.
What is the difference between APY and interest rate?
APY includes the effect of compounding; the interest rate does not. A bank might advertise a 4.50% interest rate with 4.60% APY because compounding adds that extra 0.10%. For savings accounts, always compare APY, not the interest rate, because APY shows what you actually earn.
Do I have to pay taxes on interest if I earn less than $10?
No. The bank only sends a 1099-INT form if you earn $10 or more in a calendar year. However, you must still report any interest income you earn, even if it is less than $10, on your tax return.
Should I move my money to a different bank if rates drop?
Only if the difference is significant and you have a substantial balance. Moving $1,000 from 4.50% to 4.00% saves you $5 per year—probably not worth the effort. Moving $50,000 saves you $250 per year, which is worth a phone call. Check rates every few months and move when you find a meaningfully better option.