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, credit cards, and business loans. In exchange for the use of your money, the bank pays you interest, which is a percentage of your balance. The more money you keep in the account and the longer you keep it there, the more interest you earn.
The bank sets the interest rate, and that rate changes based on what the Federal Reserve does with its own rates. When the Fed raises rates, banks usually raise what they pay savers. When the Fed lowers rates, savings rates fall too. This means the interest rate you see today may not be the same six months from now.
Interest gets added to your account automatically on a schedule set by the bank — usually daily, monthly, or quarterly. You do not have to do anything to earn it beyond keeping money in the account.
Key Takeaways
- Interest rates on savings accounts vary by bank and change when the Federal Reserve adjusts its rates.
- Higher-yield savings accounts and money market accounts typically pay more interest than traditional savings accounts at the same bank.
- Interest compounds when the bank adds earned interest back to your balance, so you then earn interest on that interest.
- The amount you earn depends on three things: your balance, the interest rate, and how often interest is added to your account.
- Online banks usually pay higher rates than brick-and-mortar banks because they have lower operating costs.
How interest rates differ between account types
Not all savings accounts pay the same rate. A traditional savings account at a large national bank might pay 0.01% annual interest, while a high-yield savings account at an online bank might pay 4% or higher. The difference is real money: on a $10,000 balance, 0.01% earns $1 per year, while 4% earns $400 per year.
The main reason for this gap is cost. Large banks with thousands of branches have high expenses — rent, staff, technology. They pass some of those costs to customers by paying lower interest. Online banks have no physical branches, so they spend less money to operate and can pass those savings to you in the form of higher rates.
Money market accounts and certificates of deposit (CDs) also pay interest, often at higher rates than savings accounts. A money market account works like a savings account but may require a larger opening balance and limits how many withdrawals you can make per month. A CD locks your money away for a set period — three months, one year, five years — and pays a fixed rate that does not change, even if the Fed raises rates later.
Understanding compound interest and how it grows your money
Compound interest means the bank adds interest to your balance, and then you earn interest on that interest. This is how savings grow faster over time, even without adding new deposits.
Here is a straightforward example: you put $1,000 in an account earning 4% annual interest. After one year, the bank adds $40 in interest, so your balance is now $1,040. The next year, you earn 4% on $1,040, not just the original $1,000. That is $41.60 in interest. The year after that, you earn 4% on $1,081.60, and so on. The longer the money sits, the more the compounding effect adds up.
How often interest compounds matters. Some banks add interest daily, some monthly, some quarterly. Daily compounding grows your money slightly faster than monthly compounding because you earn interest on your interest more frequently. The difference is small on modest balances, but it adds up over years.
What affects how much interest you actually earn
Three factors determine your interest earnings: your account balance, the annual interest rate, and how often the bank adds interest to your account.
Your balance is straightforward — the more money you keep in the account, the more interest you earn. If you have $5,000 earning 4% annually, you earn about $200 per year. If you have $10,000 at the same rate, you earn about $400 per year.
The annual interest rate is what the bank advertises, often called the APY (annual percentage yield). This rate includes the effect of compounding, so it is the true picture of what you will earn in a year. Banks are required to show you the APY before you open the account.
How often interest compounds also matters, though the effect is smaller. An account compounding daily will earn slightly more than one compounding monthly, all else equal. Most online banks compound daily, which is one reason they are competitive even when their advertised rates are close to other banks' rates.
How to compare interest rates across banks
Interest rates change constantly, so the rate you see today may not be available tomorrow. When you are ready to open an account, check the current rates at several banks rather than relying on rates you saw last week.
Look for the APY, not just the interest rate. APY includes compounding, so it is the number that matters for comparing accounts. A bank advertising "4% interest" might actually be paying 4.08% APY when you account for daily compounding.
Check whether the rate applies to your entire balance or only to balances above a certain amount. Some banks pay higher rates on balances over $25,000, for example. If your balance is smaller, you might earn a lower rate even at the same bank.
Also verify that the rate is not a promotional offer that expires after a few months. Some banks offer high rates to new customers for 90 days, then drop the rate significantly. Read the account terms or call the bank to ask how long the advertised rate lasts.
Why your interest rate might change
Banks change savings rates based on what the Federal Reserve does. The Fed does not set savings rates directly, but it sets a target range for the federal funds rate, which is the interest rate banks charge each other for overnight loans. When the Fed raises this rate, banks have less incentive to borrow from each other, so they compete harder for customer deposits by raising savings rates. When the Fed lowers rates, banks lower what they pay savers.
Your bank can also change your rate independently, though this is less common. If your bank is acquired by another bank, rates may change. If a bank decides to reduce its savings products, it might lower rates to discourage new deposits.
You have no control over these changes, but you can switch banks if your rate drops and you find a better rate elsewhere. There is no penalty for moving your money to a different bank's savings account.
Taxes on interest earnings
Interest you earn is taxable income. If you earn $100 in interest during a calendar year, you owe income tax on that $100, just as you would on wages.
At the end of each year, your bank sends you a form called a 1099-INT if you earned $10 or more in interest. You report this amount on your tax return. The tax you owe depends on your total income and your tax bracket — the higher your income, the higher the tax rate on the interest.
This is one reason why even high interest rates on small balances do not make you rich. If you have $5,000 earning 4% annually, you earn $200 in interest. If you are in the 22% tax bracket, you owe about $44 in taxes on that interest, leaving you with about $156 in actual gain.
Frequently Asked Questions
Can I lose money in a savings account?
You cannot lose your principal balance in a savings account — the bank guarantees your deposits up to $250,000 through FDIC insurance. However, if inflation is higher than your interest rate, your money loses purchasing power. If you earn 1% interest but inflation is 3%, your money is effectively worth less each year.
How often should I check my interest rate?
Check rates when you are shopping for a new account or when the Fed announces a rate change. You do not need to check constantly — rates do not change daily for individual accounts. If you notice your bank's rate has dropped significantly below other banks, that is a good time to compare options.
Is a high-yield savings account safe?
Yes, as long as the bank is FDIC-insured, which nearly all banks are. Your deposits are protected up to $250,000 per account. Online banks that offer high-yield accounts are just as safe as traditional banks — the higher rate comes from lower operating costs, not from taking more risk with your money.
What happens to my interest if I withdraw money mid-month?
This depends on your bank's rules. Most banks calculate interest based on your daily balance, so if you withdraw money partway through the month, you earn interest only on the balance you actually held. Some banks use different methods, so check your account terms or ask your bank.
Should I move my money to chase a higher rate?
If the rate difference is significant and you plan to keep the money there for at least a year, it may be worth switching. Moving $10,000 from a 0.5% account to a 4% account saves you about $350 per year. However, if you are moving small amounts frequently, the effort may not be worth the gain.