What determines how much interest you earn

The amount of interest a savings account earns depends on three things: the interest rate the bank offers, how much money you keep in the account, and how long it stays there. A bank offering 4.5% annual percentage yield (APY) on $10,000 will pay you roughly $450 per year, but only if the full $10,000 stays untouched for twelve months. If you withdraw $5,000 after six months, you earn interest only on the remaining $5,000 for the second half of the year.

The interest rate itself varies by bank and changes over time. Online banks typically offer higher rates than brick-and-mortar banks because they have lower overhead costs. The Federal Reserve's decisions about short-term interest rates also affect what banks offer — when the Fed raises its benchmark rate, savings account rates usually rise within weeks or months. When the Fed cuts rates, bank rates follow downward.

How often the bank compounds your interest — daily, monthly, or quarterly — also matters, though the difference is usually small. Daily compounding means the bank calculates interest on your balance every day and adds it back to your account, so you earn interest on that interest the next day. Monthly compounding does this once a month. Over a year, daily compounding on a $10,000 balance at 4.5% APY yields about $460, while monthly compounding yields about $459. The APY figure already accounts for compounding frequency, so you can compare rates directly across banks.

Key Takeaways

  • Interest earned equals the account balance multiplied by the APY, divided by 12 for monthly earnings — so $10,000 at 4.5% APY earns roughly $37.50 per month.
  • Online banks currently offer higher rates (often 4% to 5% APY) than traditional banks (often 0.01% to 0.5% APY) because they spend less on physical branches.
  • The Federal Reserve's interest rate decisions flow through to savings account rates within weeks, so rates you see today may be different in three months.
  • Withdrawals reduce your balance when ready, so taking out money mid-month means you earn less interest that month on the amount you removed.

How banks calculate your monthly earnings

The formula is straightforward: multiply your account balance by the APY, then divide by 12. A $25,000 balance at 4.5% APY earns $25,000 × 0.045 ÷ 12 = $93.75 per month. This assumes your balance stays constant. If your balance changes during the month, the bank typically calculates interest based on your daily balance and compounds it, which is why the exact amount varies slightly from month to month.

Most banks show you the interest earned in your account statement or online dashboard. You can see the interest posted as a separate line item, usually labeled "Interest Paid" or "Interest Income." Some banks post interest monthly, others quarterly. The timing does not affect how much you earn over a year — it only affects when you see the money appear in your account.

Why savings account rates change

Banks adjust their savings rates in response to the Federal Reserve's actions. The Fed does not set savings account rates directly — it sets the federal funds rate, which is the rate banks charge each other for overnight loans. When this rate rises, banks have more incentive to offer higher savings rates to attract deposits. When it falls, banks lower their rates because they need fewer deposits.

The lag between a Fed rate change and a bank rate change is usually two to four weeks. Some banks move faster than others. Online banks tend to raise rates quickly when the Fed increases rates, because they compete heavily on rate. Traditional banks may move more slowly because they rely on branch customers who are less likely to shop around.

Rate cuts happen more slowly. When the Fed lowers rates, banks often keep savings rates flat for a while before cutting them, hoping customers will not notice and move their money elsewhere. This is why you may see savings rates stay high for a few months after the Fed starts cutting, then drop sharply.

Comparing rates across different account types

A standard savings account at a large national bank currently earns between 0.01% and 0.5% APY. An online savings account at a bank like Marcus, Ally, or American Express Bank earns between 4% and 5.35% APY, depending on the bank and the current rate environment. A money market account (which functions like a savings account but may offer a debit card) earns similar rates to online savings accounts, usually within 0.1% of each other.

Certificates of deposit (CDs) lock your money away for a set term — three months, six months, one year, five years — and pay a fixed rate for that entire period. A one-year CD currently earns between 4.5% and 5.5% APY at online banks. The longer the term, the higher the rate, but you cannot withdraw the money without paying a penalty. A high-yield savings account has no lock-in period, so you can withdraw whenever you want, which is why it pays slightly less than a CD of the same length.

How much interest you actually keep after taxes

Interest income is taxable. The bank will send you a 1099-INT form at the end of the year if you earned $10 or more in interest, and you must report this on your tax return. The tax rate depends on your overall income and tax bracket. If you are in the 22% federal tax bracket and earn $500 in interest, you owe roughly $110 in federal tax on that interest, leaving you with $390.

Some states also tax interest income. New York, for example, taxes interest at your ordinary income tax rate. Other states like Florida and Texas do not tax interest at all. Your effective after-tax return depends on where you live and your tax situation. A high-yield savings account earning 4.5% APY might net you only 3.5% after taxes if you are in a higher tax bracket, though this varies widely.

When a savings account makes sense versus other options

A savings account is the right choice if you need the money within one to three years and want zero risk. The Federal Deposit Insurance Corporation (FDIC) insures deposits up to $250,000 per account holder per bank, so your principal is protected. You earn more interest than keeping cash in a checking account, and you can withdraw without penalty.

A CD makes sense if you know you will not need the money for a specific period and want to lock in a rate. If rates are currently 5% and you expect them to fall, a one-year CD locks in that 5% for twelve months. If you withdraw early, you pay a penalty — typically three to six months of interest — so only use a CD if you are confident you will not need the money.

Money market funds and Treasury bills are alternatives if you have a larger amount ($10,000 or more) and want slightly higher returns. Money market funds are not FDIC-insured but are very low-risk. Treasury bills are backed by the U.S. government and currently yield between 4.5% and 5.3% depending on the term. Both require a brokerage account to purchase.

How to find the highest rates available right now

Rate comparison sites like Bankrate, DepositAccounts, and NerdWallet list current rates from dozens of banks and update them daily. These sites show APY, minimum balance requirements, and whether the bank charges monthly fees. You can filter by account type (savings, money market, CD) and term length.

Online banks almost always offer higher rates than traditional banks. If you currently bank with a large national bank like Chase or Bank of America, moving your savings to an online bank like Ally, Marcus, or American Express Bank will typically increase your earnings by 4% to 5% APY. The process takes about five minutes — you provide your routing number and account number, and the bank links your accounts so you can transfer money electronically.

Before opening an account, check whether the bank charges monthly maintenance fees, requires a minimum balance, or limits the number of withdrawals per month. Most online savings accounts have no fees and no minimums, but some older accounts or specialty accounts may. Read the account terms before you open it.

Frequently Asked Questions

How much interest will I earn on $5,000 in a savings account?

At 4.5% APY, $5,000 earns roughly $225 per year, or about $18.75 per month. At 0.5% APY (typical for a traditional bank), the same $5,000 earns $25 per year. The difference between a high-yield account and a traditional bank account is $200 per year on this balance — enough to matter if you keep the money there long-term.

Does interest compound daily or monthly?

Most online banks compound interest daily, meaning they calculate and add interest to your balance every day. The APY figure already accounts for this compounding, so you do not need to do separate math. A few banks compound monthly or quarterly, but the difference in your actual earnings is less than 1% per year.

What happens to my interest if I withdraw money mid-month?

You earn interest only on the balance you held for the full period. If you have $10,000 on the first of the month and withdraw $5,000 on the fifteenth, you earn interest on $10,000 for fifteen days and $5,000 for the remaining fifteen days. The bank calculates this automatically using your daily balance.

Will savings account rates go up or down next year?

This depends on what the Federal Reserve does, which is impossible to predict with certainty. If the Fed cuts rates, savings account rates will fall within weeks or months. If the Fed holds rates steady or raises them, savings rates may stay flat or rise. Checking the Fed's recent statements and economic forecasts can give you a sense of the direction, but rates change frequently.

Is a savings account better than keeping money in a checking account?

Yes, if you do not need to access the money regularly. A savings account earns 4% to 5% APY at online banks, while a checking account typically earns 0% to 0.5%. On $10,000, that difference is $400 to $500 per year. The trade-off is that some savings accounts limit free withdrawals to six per month, though most online banks have removed this limit.