What Your Bank Does With Your Money

When you deposit money into a savings account, the bank lends that money to other customers—for mortgages, car loans, credit cards, and business lines of credit. The bank charges those borrowers interest. Your savings account interest rate is the bank's way of sharing a small portion of what it collects from borrowers. The rate is expressed as an annual percentage yield, or APY, which tells you how much your balance will grow in a year if you leave the money untouched.

The actual dollar amount you earn depends on three things: how much money you have in the account, what the APY is, and how long the money sits there. A $10,000 balance at 4.5% APY earns roughly $450 in a year. The same balance at 0.01% APY earns about $1. The difference between a high-yield savings account and a traditional bank account can mean hundreds of dollars per year on the same deposit.

Banks set their own rates based on what the Federal Reserve does. When the Fed raises its benchmark interest rate, banks have more room to offer higher rates on savings accounts—but they do not have to, and many do not. When the Fed cuts rates, banks typically lower savings rates quickly. This is why the rate you see today may not be the rate you earn six months from now.

Key Takeaways

  • Your savings account interest is money the bank pays you for letting it use your deposit, expressed as an annual percentage yield (APY).
  • The dollar amount you earn each year equals your balance multiplied by the APY—a $5,000 balance at 4% APY earns roughly $200 annually.
  • Banks change their rates whenever they choose, usually in response to Federal Reserve decisions, so your rate can drop without notice.
  • High-yield savings accounts at online banks typically offer rates two to four times higher than traditional brick-and-mortar banks.
  • Interest compounds, meaning you earn interest on your interest, but how often that happens (daily, monthly, yearly) affects your total earnings.

How Compounding Multiplies Your Money Over Time

Compounding means the bank calculates interest on your interest, not just on your original deposit. If you earn $10 in interest one month, the next month's interest is calculated on your balance plus that $10. The more often interest compounds, the more you earn—daily compounding beats monthly compounding, which beats yearly compounding.

Most savings accounts compound interest daily, which means the bank calculates what you owe every single day and adds it to your balance. Even though you see one interest deposit per month or per quarter, the daily calculation means you earn slightly more than you would if interest compounded monthly. Over a year, the difference between daily and monthly compounding on a $10,000 balance at 4.5% APY is roughly $20—small but real.

The APY already factors in compounding, so you do not have to do the math yourself. When a bank advertises 4.5% APY, that number assumes daily compounding and tells you the actual return you will see in a year. The older term, APR (annual percentage rate), does not include compounding, so it will always look slightly lower than the APY for the same account.

Why Different Banks Offer Different Rates

Banks compete for deposits, but not all of them compete on rate. Large national banks with thousands of branches and heavy advertising budgets often offer rates near zero because they do not need to attract deposits—customers come for the convenience and the brand name. Online banks have no physical branches and lower overhead, so they can afford to offer much higher rates and still make a profit.

Credit unions, which are member-owned rather than shareholder-owned, sometimes offer competitive rates as a benefit to members. However, you must meet membership requirements—living in a certain area, working for a certain employer, or belonging to a certain organization—to open an account.

The rate environment also matters. When the Federal Reserve holds rates high, banks have more incentive to offer competitive savings rates because they can still profit. When rates are falling, banks lower savings rates faster than they lower borrowing rates, which is why your savings rate can drop sharply even when the Fed only cuts by a small amount.

What Happens to Your Rate When the Fed Changes Course

The Federal Reserve does not set savings account rates directly. Instead, 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 more room to offer higher savings rates. When the Fed cuts, banks typically lower savings rates within days or weeks.

The lag works differently in each direction. When rates are rising, online banks often raise their savings rates quickly to attract deposits. When rates are falling, banks lower savings rates almost when ready, even though they do not lower borrowing rates as fast. This is why a savings account rate can drop from 4.5% to 3.5% in a month, but it takes much longer for rates to climb back up.

You cannot lock in a rate on a regular savings account the way you can with a certificate of deposit (CD). Your rate is variable, meaning it can change at any time. Banks are required to notify you before they lower your rate, but the notification often comes after the change takes effect. Reading your monthly statement or logging into your account is the most reliable way to notice when your rate has changed.

How to Compare Rates Across Banks

The only number that matters when comparing savings accounts is the APY, not the APR. The APY already includes compounding and tells you the true annual return. Look for accounts that compound daily—most do, but it is worth confirming.

Check the fine print for rate tiers. Some banks offer higher rates only on balances above a certain threshold—for example, 4.5% APY on balances of $25,000 or more, but only 2% on smaller balances. If your balance falls below the threshold, your rate drops. Other banks offer the same rate on all balances, which is simpler to track.

Also confirm that the account is FDIC-insured (or NCUA-insured if it is a credit union). This means your deposit is protected up to $250,000 if the bank fails. A slightly higher rate at an uninsured institution is not worth the risk.

The Relationship Between Your Balance and Your Earnings

Interest earnings scale linearly with your balance. Double your balance, and you double your annual interest. A $1,000 balance at 4% APY earns about $40 per year. A $10,000 balance at the same rate earns about $400. This is why moving money from a checking account (which typically earns 0% or near-zero interest) to a savings account can make a real difference if you have a substantial balance.

However, the interest you earn on a savings account is taxable income. The bank will send you a 1099-INT form at the end of the year if you earned $10 or more in interest. You must report this on your tax return. This means your actual after-tax return is lower than the APY—how much lower depends on your tax bracket. Someone in the 24% tax bracket who earns $400 in interest will owe roughly $96 in federal taxes on that amount.

When a Savings Account Rate Drops and What You Can Do

If your bank lowers your rate and you have a substantial balance, moving to a higher-rate account is worth considering. The process is straightforward: open a new account at another bank, transfer your balance, and close the old account. Most banks can process an external transfer in three to five business days.

Before you move, check whether your current bank has a promotional rate that is about to expire. Some banks offer 4.5% or higher for the first three or six months, then drop to a much lower rate. If you are in a promotional period, moving now makes sense. If your rate just dropped from a promotional level to the standard rate, that was disclosed when you opened the account.

Keep in mind that opening multiple savings accounts in a short period can affect your credit score slightly, though the impact is usually small and temporary. If you plan to move money around, space out account openings by a few weeks if you can.

Frequently Asked Questions

Does the interest I earn count as income for taxes?

Yes. Any interest your savings account earns is taxable income. If you earn $10 or more in a calendar year, the bank sends you a 1099-INT form, and you must report it on your tax return. The amount you owe in taxes depends on your tax bracket—someone in the 22% bracket pays roughly 22 cents in federal tax for every dollar of interest earned.

Can I lose money in a savings account?

No, as long as the account is FDIC-insured and your balance stays under $250,000. The bank cannot take money from your account without your permission. Your balance can shrink if you withdraw money, but the bank itself cannot reduce it. Interest earnings can also be negative in real terms if inflation is higher than your APY, meaning your purchasing power declines even though your dollar balance grows.

What is the difference between APY and APR?

APY (annual percentage yield) includes the effect of compounding and shows your true annual return. APR (annual percentage rate) does not include compounding. For savings accounts, APY is always slightly higher than APR. Banks advertise APY because it looks better, and it is the number you should use when comparing accounts.

Why do online banks offer higher rates than big national banks?

Online banks have no physical branches and lower operating costs, so they can offer higher rates and still profit. Large national banks rely on convenience and brand recognition to attract deposits, so they do not need to compete on rate. Both are safe as long as they are FDIC-insured.

If I move my money to a different bank, do I lose the interest I already earned?

No. Interest you have already earned stays in your account and moves with you when you transfer. You only stop earning the old rate once the transfer is complete and your account is closed. Any interest earned between your last statement and the closing date will be paid out or transferred along with your balance.