Interest is money the bank pays you for letting them use your deposits
When you put money in a savings account, the bank lends that money to other customers — for mortgages, car loans, business loans. In return, the bank pays you interest, which is a percentage of your balance. The bank keeps the difference between what it pays you and what it charges borrowers.
The amount you earn depends on three things: how much money you have in the account, how long it stays there, and the interest rate — the percentage the bank promises to pay you. A higher rate means more money in your pocket. A lower rate means less, even if your balance is large.
You do not have to do anything to earn interest. Once you open the account and deposit money, the bank calculates and adds interest automatically, usually every month or every day. The interest gets added to your balance, so next month you earn interest on the interest too — that compounding effect is why leaving money untouched can matter.
Key Takeaways
- Interest rates vary by bank and by account type, so comparing rates before you open an account can mean hundreds of dollars difference over a year.
- The interest rate is usually shown as an annual percentage yield (APY), which already includes the effect of compounding.
- You can find the current rate on the bank's website, by calling, or by asking in person — rates change frequently and are not locked in.
- Money market accounts and certificates of deposit (CDs) typically pay higher rates than regular savings accounts, but with different rules about when you can withdraw.
Annual Percentage Yield (APY) is the rate you actually earn
Banks advertise interest rates in a specific format called Annual Percentage Yield, or APY. This is the percentage of your balance you will earn over one year, and it already includes compounding — the effect of earning interest on your interest.
For example, if a bank offers 4.50% APY on a savings account and you deposit $1,000, you will earn roughly $45 in the first year (though the exact amount depends on how often the bank compounds interest). If you leave that $1,000 untouched for a second year at the same rate, you earn interest on $1,045, not just the original $1,000.
APY is different from Annual Percentage Rate, or APR, which you see on loans and credit cards. APY is what you want to see on savings accounts. Always compare APY numbers when you are deciding between banks, because even a difference of 1% can mean $100 extra per year on a $10,000 balance.
Interest rates change, and they are not locked in when you open an account
Banks set their own interest rates based on what the Federal Reserve does and what other banks are offering. When the Federal Reserve raises its rates, banks usually raise savings rates too. When the Fed lowers rates, bank rates fall. This happens regularly, sometimes several times a year.
The rate you see advertised today is not a promise for next year. The bank can lower your rate at any time, though they must notify you first — usually by mail or email. If you want to lock in a rate, you need a Certificate of Deposit (CD), which guarantees a specific rate for a set time period, like six months or one year.
This is why checking rates periodically matters. If your bank's rate drops significantly below what other banks offer, you can move your money to a higher-paying account. There is no penalty for switching banks with a regular savings account.
Where to find your bank's current interest rate
The easiest place to check is your bank's website. Look for a page labeled "Savings Accounts" or "Rates and Terms." The APY should be listed clearly, often with a note about when the rate was last updated.
If you cannot find it online, call the bank's customer service line or visit a branch in person. Ask specifically for the APY on the savings account type you have or want to open. Write down the rate and the date you checked it, so you can compare it to other banks.
You can also use comparison websites that list rates from multiple banks side by side. These sites do not offer accounts themselves — they just show you what different banks are currently paying. The rates on these sites are usually updated daily or weekly, so they give you a quick snapshot of the market.
How to calculate how much interest you will earn
The basic formula is straightforward: multiply your balance by the APY, then divide by 12 to get the monthly earnings. For a $5,000 balance at 4.50% APY, you would earn roughly $18.75 per month ($5,000 × 0.045 ÷ 12).
This is an estimate because the actual amount depends on how often the bank compounds interest — whether it adds interest daily, monthly, or quarterly. Daily compounding earns you slightly more than monthly compounding, because you earn interest on your interest more frequently. Most banks compound daily or monthly, and the difference is usually small.
Your bank statement will show the exact interest you earned each month. You can also log into your online banking account and look at your transaction history to see interest deposits. This is the most accurate way to track what you are actually earning.
Higher rates are available in money market accounts and CDs
If you want to earn more interest, you have two main options. A money market account is a hybrid between a checking and savings account — it usually pays a higher rate than a regular savings account, but it may have a higher minimum balance requirement and limits on how many times you can withdraw per month.
A Certificate of Deposit (CD) typically pays the highest rate, but with a catch: you agree to leave your money in the account for a set time, like three months, one year, or five years. If you withdraw before that time is up, you pay a penalty — usually a few months' worth of interest. CDs make sense if you know you will not need the money for a while.
Compare the rates across all three account types at your bank before deciding. A money market account might pay 4.75% APY, while a regular savings account pays 4.50%, and a one-year CD pays 5.00%. The difference adds up if you have a large balance.
Interest is taxable income
The interest you earn on a savings account counts as income for tax purposes. At the end of each year, your bank sends you a form called a 1099-INT that reports how much interest you earned. You report this amount on your tax return.
This matters most if you have a large balance or a high interest rate. If you earned $50 in interest, that $50 is taxable income. If you earned $500, that is also taxable. The amount of tax you owe depends on your overall income and tax bracket, but the interest is definitely counted.
Keep your bank statements and the 1099-INT form for your records. If you have questions about how to report the interest, ask a tax professional or contact the IRS — they have free resources for basic tax questions.
Frequently Asked Questions
Why do some banks pay more interest than others?
Banks set their own rates based on their costs and competition. Online banks often pay higher rates because they have lower overhead than brick-and-mortar branches. Large national banks sometimes pay lower rates because they do not need to compete as aggressively for deposits. Shop around — the difference can be significant.
Can I lose money if the interest rate drops?
No. The interest rate dropping means you will earn less going forward, but the money you already have stays in your account. Your balance will not shrink because of a rate cut. You just earn less interest each month than you did before.
What happens to my interest if I withdraw money mid-month?
Most banks calculate interest based on your daily balance, so if you withdraw money partway through the month, you earn interest only on the amount you had for the days you held it. Some banks use a different method, so check your account terms or ask your bank how they handle this.
Is there a minimum balance to earn interest?
It depends on the bank and account type. Some savings accounts have no minimum and pay interest on any balance. Others require a minimum like $500 or $1,000 to earn the advertised rate. Check the account terms before you open it, because falling below the minimum might mean a lower rate or no interest at all.
Should I move my money to a higher-paying bank?
If your current bank pays significantly less than others — more than 1% difference — it might be worth moving. Calculate how much extra you would earn in a year at the higher rate, then decide if it is worth the effort to switch. For small balances, the difference may not justify the hassle.