What determines how much interest you make

The amount your 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 sits there. The bank sets the rate — you do not negotiate it. The rate changes based on what the Federal Reserve does with its benchmark rate, which moves several times a year. When the Fed raises rates, banks typically raise savings rates within weeks. When the Fed cuts rates, savings rates fall.

Your balance matters because interest compounds. If you have $10,000 earning 4.5% annually, you make roughly $450 in the first year. If you leave that $450 in the account, the next year you earn interest on $10,450, not just the original $10,000. The longer money sits untouched, the more compounding works in your favor.

The frequency of compounding also matters. Some banks compound interest daily, others monthly. Daily compounding means you earn slightly more because interest gets added to your balance more often, and then you earn interest on that interest sooner. The difference is small — usually less than 0.1% annually — but it adds up over years.

Key Takeaways

  • Your earnings depend on the interest rate your bank offers, your account balance, and how long the money stays in the account.
  • Banks change savings rates when the Federal Reserve moves its benchmark rate, usually within a few weeks of a Fed decision.
  • Interest compounds, meaning you earn returns on your previous returns — the longer money sits, the more this effect compounds.
  • Online banks typically offer higher rates than brick-and-mortar banks because they have lower operating costs.
  • The rate you see advertised is the annual percentage yield (APY), which already accounts for compounding, so you can compare rates directly between banks.

How to find the current rate your bank is offering

Your bank publishes its savings rate on its website, usually in a table labeled "Rates and APY" or "Deposit Rates." The rate you see there is the annual percentage yield, or APY. This is the actual return you will earn in a year, including the effect of compounding. It is different from the interest rate itself, which does not account for compounding — but most banks now show APY instead of the raw rate, so you do not have to do the math.

If you already have an account, log into your online banking portal and look for a section called "Account Details" or "Account Information." Your current rate should appear there. If it does not, call the bank's customer service line — they can tell you the exact rate on your specific account. Rates sometimes vary slightly by account type or balance tier, so asking directly is faster than searching the website.

Compare rates across banks using a rate-tracking site like Bankrate, DepositAccounts, or the FDIC's National Rates and Rate Caps table. These sites update daily and show which banks are offering the highest rates at any given moment. Rates change frequently — sometimes weekly — so a bank offering 4.5% one month might drop to 4.25% the next.

The difference between what online banks and traditional banks pay

Online banks typically offer 0.5% to 1.5% higher APY than brick-and-mortar banks. A traditional bank might offer 0.01% while an online bank offers 4.5% on the same type of account. The reason is cost: online banks have no physical branches, no tellers, no real estate expenses. They pass those savings to customers through higher rates.

The trade-off is access. With a traditional bank, you can walk into a branch and speak to someone in person. With an online bank, you manage everything through a website or app. You can still transfer money to other banks, deposit checks by taking a photo, and withdraw cash at ATMs (though you may pay a fee if you use an ATM outside the bank's network). For most people, the higher rate makes up for the lack of a physical location.

Some hybrid banks offer both — a physical location and competitive online rates — but these are less common and rates are usually somewhere between the two extremes. If you need in-person service, the convenience may be worth accepting a lower rate. If you only need to deposit and withdraw money occasionally, an online bank usually makes more financial sense.

How to calculate what you will earn over time

The simplest way is to use a savings calculator, which most banks provide on their website. You enter your starting balance, the APY, and how many months or years you plan to keep the money there. The calculator shows you the total interest earned and your final balance.

If you want to do it yourself, the formula is: Final Balance = Starting Balance × (1 + APY)^years. For example, $10,000 at 4.5% APY for 3 years: $10,000 × (1.045)^3 = $14,116.88. You earned $1,116.88 in interest.

Keep in mind that this assumes you do not add or withdraw money during that time. If you deposit $200 a month, the calculation becomes more complex — the calculator handles this automatically, but doing it by hand requires adding up the interest on each deposit separately. Most online banking platforms also show a running total of interest earned in your account details, updated daily or monthly depending on the bank.

Why your rate might change and when

Banks change savings rates in response to Federal Reserve decisions. The Fed meets eight times a year and announces whether it is raising, lowering, or holding its benchmark rate steady. When the Fed raises rates, banks compete to attract deposits by raising their savings rates. When the Fed cuts rates, banks lower savings rates because they need fewer deposits.

The timing varies. Some banks raise rates within days of a Fed announcement. Others wait weeks or even months. Banks that are trying to attract new customers often raise rates faster than banks that already have plenty of deposits. If you are shopping for a new account, you might see a bank raise its rate right after a Fed decision, then lower it a few weeks later once deposits start flowing in.

Your existing rate is usually may provide for as long as you keep the account open, but the bank can change it at any time with notice (typically 30 days). This means if you open an account at 4.5% and the Fed cuts rates, your bank will eventually lower your rate too. There is no way to lock in a rate permanently on a savings account — that is why some people move money to a certificate of deposit (CD) when rates are high, because CDs lock in a rate for a fixed term.

When moving your money to a different bank makes sense

If your current bank's rate drops more than 0.5% below the highest rate available elsewhere, moving is usually worth considering. The process takes a few days: open an account at the new bank, transfer your money, and close the old account. There is no penalty for moving savings accounts (unlike CDs, which charge a penalty if you withdraw early).

The math is straightforward. If you have $50,000 earning 0.5% at your current bank and you can move it to a bank offering 4.5%, you gain $2,000 per year in additional interest. Even if the transfer takes a week, you come out ahead. The only reason not to move is if you value the convenience of your current bank enough to accept the lower rate.

Some people keep accounts at multiple banks to take advantage of rate changes. When one bank raises rates, they move money there. When another bank drops rates, they move money out. This works if you are comfortable managing multiple accounts, but most people find it simpler to pick one bank with competitive rates and stay there unless the rate gap becomes significant.

How taxes affect what you actually keep

Interest earned 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 marginal tax rate. Your bank will send you a 1099-INT form in January showing how much interest you earned, and you report that on your tax return.

The tax impact depends on your income bracket. If you are in the 22% tax bracket and earn $500 in interest, you owe about $110 in federal tax, leaving you with $390 in actual earnings. State income tax may explore too, depending on where you live. Some states do not tax interest income, while others tax it at rates up to 13%.

This is why the advertised APY is not the same as what you keep. A 4.5% APY might net you only 3.5% after taxes, depending on your situation. This does not change which bank you should choose — you still want the highest rate available — but it is worth knowing when you are calculating how much money you will actually have.

Frequently Asked Questions

Does my savings account earn interest every day?

Most banks compound interest daily, meaning they calculate and add interest to your balance every day. However, you typically see the total interest credited to your account monthly or quarterly. The daily compounding happens behind the scenes, but the effect is that you earn slightly more than if interest were compounded monthly.

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

You earn interest only on the money that was in the account during the period it was there. If you have $10,000 for 20 days and then withdraw $5,000, you earn interest on $10,000 for those 20 days, then interest on $5,000 for the remaining days of the month. Some banks use the average daily balance method, which calculates interest based on your balance each day.

Is there a minimum balance I need to earn interest?

Most online banks have no minimum balance requirement to earn the advertised rate. Some traditional banks require $500 or $1,000 to open an account, but once the account is open, you earn the full rate even if your balance drops below that. Check your bank's terms to be sure, because a few banks still offer lower rates on accounts below a certain balance.

Can I move my money to a higher-rate bank without losing interest?

Yes. Interest accrues through the day you withdraw the money. When you transfer to a new bank, you stop earning interest at the old bank and start earning at the new bank's rate. There is no gap or penalty. The transfer itself takes one to three business days, during which your money is in transit and earning nothing, but this is unavoidable.

What if the bank goes out of business?

Your deposits are insured by the FDIC (Federal Deposit Insurance Corporation) up to $250,000 per account type per bank. If a bank fails, the FDIC pays you back in full, including any interest earned up to the date of failure. This protection applies to all FDIC-member banks, which includes virtually all banks in the United States.