CD Calculator for Interest, APY and Maturity Value
Our CD calculator shows how much a certificate of deposit will earn by the end of its term. Enter your deposit, rate and term to see the interest, the APY and your balance at maturity. It also works out what you would get back after an early withdrawal.
What a CD Is
A CD, short for certificate of deposit, is a savings account that holds your money for a fixed term at a fixed rate. Terms usually run from 3 months to 5 years, and longer terms often pay more. You agree to leave the money alone until the CD matures, and the bank pays you interest for that promise.
CDs at banks are insured by the FDIC and those at credit unions by the NCUA, up to $250,000 per depositor, per institution and per ownership category. That makes them one of the safest places for cash you will not need for a while. A CD calculator shows what that safety pays before you sign up.
How to Use the CD Calculator
- Enter the amount you plan to deposit.
- Type the rate and choose whether it is an APY or a nominal rate.
- Pick how often interest compounds and set the term in months or years.
- Add your tax rate if you want to see what you keep after tax.
The results show your balance at maturity, the interest earned and a growth schedule by month or by year. Switch the mode to early withdrawal to see what you would get back if you closed the CD before the end of its term. The CD interest calculator updates as you type, so you can compare offers in seconds.
How CD Interest Is Calculated
Banks pay CD interest on the deposit plus any interest already added. The formula is balance = deposit × (1 + rate ÷ n)^(n × years), where n is the number of times interest compounds each year. Our CD interest calculator runs this math for any term, even odd ones such as 7 or 18 months.
If you want to know how to calculate CD interest by hand, start with the APY. Raise 1 plus the APY to the power of the term in years and multiply the result by the deposit. Subtract the deposit and what is left is your interest, the same figure the CD calculator shows.
APY vs Interest Rate
The annual percentage yield is the rate you actually earn in a year once compounding is included. The nominal rate, often listed as the interest rate or APR, leaves compounding out. A 4.5% nominal rate compounded daily works out to an APY of about 4.60%.
US banks must show the APY on deposit accounts under the Truth in Savings Act. Comparing APYs is the fair way to line up offers. Choose the APY option in the CD interest calculator when you copy a rate from a bank website.
How Compounding Changes the Result
At the same nominal rate, more frequent compounding pays a little more. The table below shows a 4.5% nominal rate under each schedule. On $10,000, monthly and daily compounding differ by less than $1 a year.
| Compounding | APY |
| Annually | 4.500% |
| Quarterly | 4.577% |
| Monthly | 4.594% |
| Daily | 4.602% |
| Continuously | 4.603% |
CD Calculator Examples
A 12 Month CD
You deposit $10,000 in a 12 month CD paying 4.5% APY. The CD calculator shows a balance of $10,450 at maturity, so you earn $450 in interest. That is an average of $37.50 a month.
A 5 Year CD
Put the same $10,000 in a 5 year CD at 4.5% APY and the CD calculator gives $12,461.82. You earn $2,461.82, more than five times the 1 year result, because each year's interest also earns interest. At 4% APY the same deposit would end at $12,166.53.
Early Withdrawal Penalties
Most banks charge a fee if you take money out of a CD before it matures. The early withdrawal penalty is usually a set number of months of interest, such as 3 months on short terms and 6 to 12 months on longer ones. Some banks charge it on the amount withdrawn and others on the whole balance.
Say you put $10,000 in a 12 month CD at 4.5% APY and close it after 6 months with a 3 month penalty. You would have earned $222.52 and the penalty would be about $110.05, so you keep $112.48. If you closed it after only 2 months with a 6 month penalty, the $220.10 fee would be larger than the $73.63 you earned and would eat into your deposit.
The early withdrawal mode of the CD calculator runs these numbers for any term. Check the early withdrawal penalty before you open an account. A no penalty CD pays a bit less, and the CD interest calculator shows how much.
Taxes on CD Interest
CD interest counts as ordinary income in the US, and banks send Form 1099-INT when you earn $10 or more in a year. You owe tax on interest as it is credited, even if the money stays in the CD. Enter your tax rate in the CD interest calculator to see what you keep. In the 22% bracket, the $450 earned on a 12 month CD would cost $99 in federal tax and leave you $351.
CD Returns After Inflation
A CD protects your deposit, but inflation still reduces what the money can buy. If your CD pays 4.5% APY and prices rise 3% a year, your real gain is only about 1.46%. When inflation runs above the CD rate, your balance grows while its buying power falls. Check recent price changes with our Inflation Calculator before you lock in a long term.
Building a CD Ladder
A ladder spreads your savings across several CDs that mature at different times. Instead of putting $20,000 into one 5 year CD, you could split it into five CDs of $4,000 with terms of 1 to 5 years. Each year one CD matures, and you can use the cash or roll it into a new 5 year CD. With sample rates from 3.8% to 4.2% APY, the CD interest calculator gives the values below.
| Rung | APY | Value at maturity |
| 1 year | 3.8% | $4,152.00 |
| 2 years | 3.9% | $4,318.08 |
| 3 years | 4.0% | $4,499.46 |
| 4 years | 4.1% | $4,697.46 |
| 5 years | 4.2% | $4,913.59 |
A ladder gives you regular access to part of your money without paying penalties. It also softens the risk of locking everything in just before rates rise. Once the ladder is built, every rung earns the higher long term rate, which the CD interest calculator lets you check.
CDs Compared With Other Savings
- High yield savings accounts let you withdraw at any time, but their rates can change overnight.
- Treasury bills are backed by the US government, and their interest is free from state and local tax.
- Brokered CDs can be sold before maturity, though the price may be below what you paid.
A CD suits money with a clear date, such as a house deposit next year. Keep your emergency fund where you can reach it without a fee. The CD interest calculator helps you compare a fixed CD rate with a savings rate that may fall.
Why Use Our CD Calculator
Our CD interest calculator works with an APY or a nominal rate, any compounding schedule and any term from 1 month up. You also get a growth schedule, an after tax balance and an early withdrawal check in one place. It runs in your browser and nothing you enter is stored. Enter your deposit and see what your CD will earn now.
Frequently asked questions
Is this CD calculator free?
Yes, it is free to use with no sign up and no limit.
How to calculate CD interest on a deposit?
Multiply the deposit by (1 + APY) raised to the term in years, then subtract the deposit.
What is the difference between APY and interest rate?
The annual percentage yield includes compounding, while the nominal interest rate does not.
Does the CD interest calculator include taxes?
Yes, enter your tax rate to see the interest and balance after tax.
What is a CD ladder?
It is a set of CDs with staggered terms, so part of your money matures every year.
Which compounding should I pick in the CD interest calculator?
Use the schedule your bank lists, or choose APY and the compounding no longer changes the result.
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