What a CD will earn depends on the rate, the amount you deposit, and how long you lock the money away

A CD earns money through interest—a percentage of your deposit that the bank pays you for letting them hold your cash. The three things that change how much you earn are the interest rate the bank offers, how much you put in, and the term length (how many months or years before the CD matures). A $5,000 CD at 4.5% for one year will earn roughly $225. The same $5,000 at 5.5% for the same year earns roughly $275. Longer terms usually pay higher rates, so a two-year CD at the same bank might pay 5.0% or more.

The math is straightforward: multiply your deposit by the annual rate, then multiply by the number of years. A $10,000 CD earning 5% annually for three years earns about $1,500 total (before taxes). But banks calculate interest differently—some compound it daily, some monthly—so the actual amount is usually slightly higher. Most banks show you the exact earnings before you open the account, so you can compare offers side by side.

Key Takeaways

  • Higher interest rates and longer terms both increase what your CD earns, but rates change weekly so comparing banks matters.
  • A $10,000 CD earning 5% for one year earns about $500; the same CD for three years earns about $1,500.
  • Banks compound interest daily or monthly, so your actual earnings are slightly higher than a simple multiplication would show.
  • You can see the exact dollar amount you will earn before you open the account—banks display this as APY (annual percentage yield).

How to calculate earnings yourself

The simplest way is to use the bank's own calculator on their website—you enter the deposit amount, the rate, and the term, and it shows you the total. But if you want to do it by hand, the formula is: Deposit × Annual Rate × Years = Interest Earned. So $5,000 × 0.05 × 2 = $500 earned over two years.

This gives you a rough number, but it is not exact because banks compound interest—they add earned interest back into your account, and then you earn interest on that interest too. The difference is usually small for short terms. A $5,000 CD at 5% for one year earns $250 with simple math, but about $256 with daily compounding. For longer terms or higher rates, the gap widens. The bank will always show you the exact amount before you commit, so you do not have to guess.

Why rates vary so much between banks

Banks set their own CD rates based on what they need to borrow and what they can earn by lending your money out. Online banks typically offer higher rates than brick-and-mortar banks because they have lower overhead costs. A local bank might offer 4.0% on a one-year CD while an online bank offers 5.25% for the same term. Over a year on $10,000, that difference is $125 in your pocket.

Rates also change weekly or even daily as the Federal Reserve adjusts its benchmark rate and as banks compete for deposits. If you see a rate you like, it may not be there next week. That does not mean you should rush—rates often move in cycles—but it does mean checking multiple banks before you decide. Websites like Bankrate and DepositAccounts list current rates across dozens of banks so you can see what is available right now.

How term length affects your earnings

Longer CDs almost always pay more than shorter ones at the same bank. A three-month CD might pay 4.0%, a one-year CD might pay 4.75%, and a three-year CD might pay 5.25%. The bank pays you more because you are agreeing to lock your money away longer, which gives them certainty about how long they can use your cash. Over $10,000, the difference between a one-year CD at 4.75% and a three-year CD at 5.25% is roughly $500 in extra earnings.

But longer terms also carry risk: if rates rise after you open the CD, you are stuck earning the lower rate until maturity. If you need the money before the term ends, you will pay an early withdrawal penalty—usually three to six months of interest. So a three-year CD earning $1,500 total might cost you $375 to $750 if you withdraw after one year. This is why many people use a CD ladder—opening multiple CDs with different maturity dates so some money comes available each year.

The difference between APY and interest rate

Banks advertise the APY (annual percentage yield), not just the interest rate. APY includes the effect of compounding, so it is the real number you should use to compare CDs. A CD with a 5.00% interest rate compounded daily might have an APY of 5.13%—that extra 0.13% is the money you earn on your earned interest. When you see a rate advertised, it is almost always the APY, so you can compare it directly across banks.

The APY is also what the bank uses to calculate your actual earnings before you open the account. If a bank shows you that a $10,000 CD will earn $513 over one year, that number is based on the APY, not the base rate. So you can trust the dollar amount the bank displays—you do not have to do any math yourself unless you want to.

What happens to your earnings when the CD matures

When your CD reaches its maturity date, the bank adds all earned interest to your account. You then have a short window—usually seven to ten days—to decide what to do with the money. You can withdraw it, move it to a savings account, or renew the CD for another term at whatever rate the bank is offering at that time. If you do nothing, most banks automatically renew the CD at the current rate, which may be higher or lower than what you were earning.

This is important: if rates have dropped, you might not want to renew at the new rate. If rates have risen, you might want to shop around instead of accepting the bank's renewal offer. Set a calendar reminder for a few weeks before your CD matures so you have time to compare options and decide whether to stay or move your money elsewhere.

How taxes reduce what you actually keep

CD interest is taxed as ordinary income, which means you owe federal income tax on the earnings. If you earned $500 in CD interest and you are in the 22% tax bracket, you owe about $110 in federal tax. Some states also tax CD interest. The bank will send you a 1099-INT form at the end of the year showing how much you earned, and you report that on your tax return.

This matters when you compare CDs to other savings options. A CD earning 5% sounds good until you realize you keep only about 3.9% after taxes (depending on your bracket). High-yield savings accounts earn the same rate and have the same tax hit, but they do not lock your money away. Treasury bonds and I Bonds have different tax treatment—I Bonds defer federal tax until you cash them, which can be useful for long-term savings. None of this changes how much the CD earns, but it changes how much you have left to spend or save.

Frequently Asked Questions

Can I earn more by opening multiple CDs at the same bank?

No. The bank pays the same rate on every CD of the same term, regardless of how many you open. Opening five $2,000 CDs earns the same total as opening one $10,000 CD. The only reason to open multiple CDs is to stagger maturity dates (a CD ladder) so you have access to some money each year without paying early withdrawal penalties.

What if I need the money before the CD matures?

You can withdraw it, but you will pay an early withdrawal penalty—usually three to six months of interest. If your CD earned $500 and the penalty is six months of interest ($250), you keep only $250 of your earnings. Some banks offer no-penalty CDs that let you withdraw without a penalty, but they pay lower rates to offset that flexibility.

Do I earn interest on interest in a CD?

Yes, through compounding. The bank adds interest to your account regularly (daily or monthly), and then you earn interest on that new balance. Over a year this adds up to a small amount—maybe 0.1% to 0.2% more than simple interest would give you—but over longer terms it becomes meaningful.

Is a CD a good way to save for a specific goal?

It depends on your timeline. If you know you will not need the money for two years, a two-year CD locks in a rate and earns more than a savings account. If you might need it sooner, the early withdrawal penalty could wipe out your earnings, so a high-yield savings account is safer even if it pays slightly less.

How do I know if a CD rate is good right now?

Check what multiple banks are offering for the same term. Bankrate, DepositAccounts, and NerdWallet all show current rates across banks. If one bank is offering 5.5% for a one-year CD and most others are at 4.75%, that is a good rate. Rates change weekly, so what is good today may not be good next month.