What a savings account actually pays you

A savings account pays you interest — a percentage of the money you keep in the account. The bank uses your money to lend to other customers or invest it, and shares a small portion of what it earns with you. The amount you make depends on three things: how much money sits in the account, what interest rate the bank offers, and how long the money stays there.

Right now, savings account rates range from nearly zero percent at some large national banks to around 4 to 5 percent at online banks and credit unions. That difference matters. On $10,000, a 0.01 percent rate earns you about $1 per year. The same $10,000 at 4.5 percent earns you about $450 per year. The bank you choose changes your earnings more than almost anything else.

Interest compounds, which means you earn money on the interest you already earned. Most banks calculate and add interest monthly or daily. If your account compounds daily, you earn a tiny bit of interest every single day, and tomorrow's interest is calculated on today's balance plus today's interest. Over months and years, this adds up — but the effect is small on amounts most people keep in savings accounts.

Key Takeaways

  • The interest rate your bank offers is the single biggest factor in how much you earn, and rates vary from near zero at large national banks to 4 to 5 percent at online banks.
  • Your earnings equal your balance multiplied by the annual interest rate divided by 12 (for monthly earnings), so $10,000 at 4.5 percent earns roughly $37.50 per month.
  • Interest compounds daily or monthly depending on the bank, meaning you earn small amounts of interest on your previous interest.
  • Keeping money in a savings account for longer earns more total interest, but the rate itself does not change based on how long you keep the money there.

How to calculate what you will earn

The formula is straightforward: multiply your account balance by the annual interest rate, then divide by 12 to get your monthly earnings. A $5,000 balance at 4 percent annual interest earns about $16.67 per month ($5,000 × 0.04 ÷ 12). A $20,000 balance at the same rate earns about $66.67 per month.

This calculation assumes your balance stays the same all month. If you add money or withdraw money, your earnings change. Some banks calculate interest on your lowest balance during the month; others use your average daily balance. Check your account agreement to see which method your bank uses — it usually appears in the fine print under "Interest Calculation" or "How Interest Is Earned."

Online calculators exist, but they all use the same math. You can also ask your bank directly what you will earn on a specific balance at their current rate. Most banks publish their rates on their website, and those rates change when the Federal Reserve changes its benchmark rate.

Why rates differ so much between banks

Large national banks like Bank of America, Chase, and Wells Fargo typically offer rates below 0.5 percent because they have high operating costs and do not need to attract deposits — people use them for convenience and brand recognition. Online banks like Marcus, Ally, and Wealthfront have lower overhead and compete on rate, so they offer 4 to 5 percent. Credit unions often fall in between, around 2 to 4 percent, depending on the union and your membership status.

The rate environment also matters. When the Federal Reserve raises its benchmark rate, banks eventually raise their savings rates too — though large banks often lag weeks or months behind. When the Fed cuts rates, banks drop their rates quickly. This means the rate you see today may not be the rate you earn six months from now.

Some banks offer promotional rates for new customers — for example, 5.35 percent for the first three months, then dropping to 4.5 percent. Read the terms carefully. Others offer higher rates only on balances above a certain threshold, like $25,000 or $100,000.

The difference between APY and APR

APY (Annual Percentage Yield) is the rate that matters for savings accounts. It includes the effect of compounding — the interest you earn on your interest. APR (Annual Percentage Rate) is used for loans and credit cards and does not include compounding. Banks are required to show you the APY, not the APR, when advertising savings rates.

The difference between APY and the stated interest rate is usually small — often less than 0.1 percent — but it is real. A bank might advertise "4.50% APY" on a savings account. That 4.50 percent already includes the compounding effect. You do not need to do anything special to get the compounding benefit; it happens automatically.

How your earnings are taxed

Interest you earn in a savings account is taxable income. If you earn $500 in interest during a calendar year, you owe federal income tax on that $500 at your ordinary income tax rate. The bank will send you a 1099-INT form in January showing how much interest you earned, and you report that on your tax return.

State income tax also applies in most states. Some states exempt interest income for people over a certain age or with income below a threshold, but most do not. The tax you owe depends on your total income and your tax bracket, not on the bank or the account type.

This is why the difference between a 0.01 percent account and a 4.5 percent account matters even more than the raw numbers suggest. On $10,000, the 4.5 percent account earns $450 before tax. After federal and state tax, you might keep $300 to $350 depending on your bracket. The 0.01 percent account earns $1 before tax, and you keep less than $1 after tax — the tax itself may exceed your earnings.

What happens to your earnings if you withdraw money

Interest accrues daily at most banks, so if you withdraw money mid-month, you still earn interest on the balance for the days you held it. If you withdraw on the 15th of a 30-day month, you earn interest on your full balance for 15 days, then on the lower balance for the remaining 15 days.

Some savings accounts have withdrawal limits or penalties for frequent withdrawals, though these rules have become less common. Check your account agreement. If your account does have limits, exceeding them might result in a fee or the account being converted to a different type of account.

The interest rate itself does not change based on your balance or how often you withdraw. A $50,000 account and a $500 account at the same bank earn the same percentage rate. The larger account straightforward earns more dollars because the percentage is applied to a larger number.

Comparing savings accounts to other places to keep money

A money market account works similarly to a savings account and often offers the same or slightly higher rates. The main difference is that money market accounts usually require a higher minimum balance and may offer limited check-writing or debit card access. The interest calculation and tax treatment are identical.

A certificate of deposit (CD) locks your money away for a set period — three months, one year, five years — in exchange for a higher rate. If you withdraw before the term ends, you pay a penalty. CDs currently offer rates 0.5 to 1 percent higher than savings accounts at the same bank, but you lose access to your money.

Treasury bills and money market funds are other options for short-term savings, but they involve different mechanics and tax treatment. For most people keeping money in a savings account, the choice comes down to finding the highest rate available, which usually means an online bank.

Frequently Asked Questions

Do I have to do anything to earn interest?

No. Interest accrues automatically once you open the account and deposit money. You do not need to opt in, set up anything, or take any action. The bank calculates and deposits interest into your account on a schedule set by the bank — usually monthly.

Can I lose money in a savings account?

No. Your principal — the money you deposit — is protected by FDIC insurance up to $250,000 per account holder per bank. Interest rates can go down, which means you earn less, but you cannot lose the money you put in. The only way to have less money than you started with is to withdraw it.

What if I move my money to a different bank?

You keep all the interest you earned up to the day you withdraw. Interest stops accruing once the money leaves your account. If you move $10,000 and earned $45 in interest, you withdraw $10,045. The new bank starts calculating interest on whatever balance you deposit with them at their rate.

Why do online banks pay more interest than big banks?

Online banks have lower costs because they do not operate physical branches. They pass those savings to customers by offering higher rates. Large banks can afford to pay less because customers stay for convenience and brand trust, not because of the rate. If you care about earning the most interest, online banks are usually the better choice.

Does the interest rate change after I open the account?

Yes. Banks change their rates regularly, usually in response to Federal Reserve decisions. Your rate can go up or down. Some accounts have promotional rates that expire after a set period. Check your bank's website or call to see what your current rate is — it may have changed since you opened the account.