What you earn depends on the rate, the amount you deposit, and how long you leave the money there

A CD pays you interest on the money you deposit. The bank tells you upfront exactly how much interest you'll earn — that's the annual percentage yield, or APY. If you deposit $5,000 in a CD with a 4.5% APY for one year, you'll earn $225 before that year ends. The longer the CD term and the higher the rate, the more you earn.

The catch is that you agree to leave your money untouched until the CD matures — usually anywhere from three months to five years. If you withdraw early, the bank charges a penalty that eats into your earnings. So the money you actually keep depends on whether you can leave it alone for the full term.

Key Takeaways

  • Your earnings equal your deposit multiplied by the APY, divided by 12 if the CD is shorter than a year — for example, $10,000 at 4% APY for six months earns about $200.
  • Banks publish their CD rates and terms on their websites, and rates change weekly or even daily, so the rate you see today may not be available next week.
  • Early withdrawal penalties can wipe out all your interest and cost you part of your original deposit, so only put money in a CD if you won't need it before maturity.
  • A longer CD term usually pays a higher rate than a shorter one from the same bank, but you lock your money away for that entire period.

How the math works: a simple example

Let's say you deposit $10,000 in a one-year CD paying 4.5% APY. Multiply $10,000 by 0.045 to get $450. That's your earnings for the full year. When the CD matures, you get back $10,450.

For a CD shorter than a year, divide the APY by 12 and multiply by the number of months. A six-month CD at 4.5% APY earns roughly $225 on $10,000 (because 4.5% ÷ 2 = 2.25%). A three-month CD at the same rate earns about $112.50.

The formula is: Deposit × APY ÷ 12 × Number of Months = Interest Earned. Most banks calculate this daily and credit it to your account when the CD matures, though some compound it monthly or quarterly — meaning you earn interest on your interest. That compounds your total slightly, but the difference is small on most CDs.

Why rates vary so much between banks and terms

Banks set CD rates based on what the Federal Reserve does with interest rates. When the Fed raises rates, banks raise CD rates to attract deposits. When the Fed cuts rates, CD rates fall. This happens constantly, so a 4.5% rate one week might be 4.2% the next.

Longer terms usually pay more than shorter ones. A five-year CD might pay 4.5% while a three-month CD pays 3.8% from the same bank. Banks do this because they want to lock your money in for longer — they can lend it out and earn more themselves. But this also means you're taking a bigger risk: if rates rise sharply after you lock in, you'll wish you'd waited.

Online banks often pay higher rates than brick-and-mortar banks because they have lower overhead costs. A national online bank might offer 4.75% on a one-year CD while a local credit union offers 4.0% for the same term. Shopping around matters.

What happens to your earnings if you withdraw early

Banks charge an early withdrawal penalty if you take your money out before the CD matures. The penalty is usually stated as a number of months of interest — for example, "180 days of interest" or "six months of interest."

If your CD pays $450 a year and the penalty is six months of interest, the penalty is $225. If you withdraw after three months, you've earned $112.50 in interest, but the penalty costs you $225, so you actually lose $112.50 from your original deposit. You'd get back $9,887.50 instead of $10,000. This is why early withdrawal should be a last resort.

Some banks charge a flat dollar amount instead of months of interest. Read the CD agreement before you open one so you know exactly what the penalty is. If you think you might need the money, a regular savings account or money market account is safer, even though it pays less.

How to compare CDs and find the best rate for your situation

Start by deciding how long you can leave the money alone. If you need it in six months, don't open a one-year CD just because the rate is higher. The penalty will cost you more than the extra interest you'd earn.

Once you've picked a term, check rates at multiple banks. Most banks list their CD rates on their websites, and you can compare them in minutes. Look at the APY, not the interest rate — APY includes compounding and is the true number you'll earn. Write down the rate, the term, and the penalty for each one you're considering.

Don't chase the absolute highest rate if it's from a bank you've never heard of. Make sure the bank is FDIC-insured, which means your deposit is protected up to $250,000 if the bank fails. Most major banks and many online banks are FDIC-insured. You can check a bank's status on the FDIC website.

What to do when your CD matures

When your CD reaches its maturity date, the bank credits your interest to your account and the CD closes. You now have the choice to open a new CD, move the money to savings, or withdraw it. The bank will usually send you a notice a few days before maturity telling you what's about to happen.

Some banks have an auto-renewal feature, which means they automatically open a new CD at the current rate if you don't tell them otherwise. This is convenient if you want to keep your money in CDs, but it can lock you in at a lower rate if rates have fallen. Read the maturity notice carefully so you know whether auto-renewal is on and what the new rate will be.

If rates have risen since you opened your CD, you might want to open a new one at the higher rate. If rates have fallen, you might prefer to move your money to a high-yield savings account instead. Either way, you have a window of time — usually a week or two — to decide before the bank acts.

The trade-off between safety and earnings

CDs pay more than savings accounts because you're agreeing to lock your money away. The longer you lock it, the more you earn. But this means you can't access your cash without a penalty, and you're betting that you won't need it before the CD matures.

If you have an emergency fund, keep it in a high-yield savings account where you can withdraw it anytime without penalty. Use CDs for money you know you won't need — a down payment you're saving for in three years, a bonus you want to set aside, money earmarked for a specific goal. That way you get the higher rate without the risk of needing the money and paying a penalty.

Frequently Asked Questions

Can I earn more by opening multiple CDs instead of one?

No. If you open five $2,000 CDs instead of one $10,000 CD at the same bank and rate, you earn the same total interest. The only reason to open multiple CDs is to spread your money across different banks to stay under the $250,000 FDIC insurance limit, or to stagger maturity dates so you have access to some money sooner.

Do I pay taxes on CD interest?

Yes. CD interest is taxable income. The bank will send you a 1099-INT form at the end of the year showing how much interest you earned, and you'll report it on your tax return. If you earned more than $10 in interest, the bank is required to send you the form.

What's the difference between APY and interest rate?

The interest rate is the percentage the bank pays. APY is the interest rate plus the effect of compounding — earning interest on your interest. APY is always equal to or higher than the interest rate, and it's the number you should use when comparing CDs, because it shows what you'll actually earn.

Is it ever worth paying the early withdrawal penalty?

Rarely. The only scenario where it makes sense is if you have a true emergency and the penalty is small — for example, if you've held the CD for most of its term and the penalty is only a few months of interest. If you're thinking about withdrawing early, ask the bank to calculate exactly how much you'd get back so you know the real cost.

Why would I choose a CD over a savings account if rates are similar?

You wouldn't, unless you want to force yourself to save by making the money harder to access. If a savings account and a CD pay nearly the same rate, the savings account is better because you can withdraw without penalty. But if the CD pays significantly more — say, 4.5% versus 3.5% — and you won't need the money, the CD is worth it.