CD Calculator
Estimate what a certificate of deposit will earn, and compare up to three offers side by side.
Results
| Offer | Final balance | Interest | After tax | Per month |
|---|
Offer 1 year by year
| Year | Interest earned | Balance |
|---|
Quick Answer
A CD's final balance equals your deposit multiplied by (1 + APY) raised to the term in years. For example, $10,000 in a 12-month CD at 4.50% APY grows to $10,450, earning $450 in interest.
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Table of Contents
How This CD Calculator Works
A certificate of deposit (CD) is a savings account that pays a set rate for a set term. This calculator grows your deposit by each offer's APY over its term, then shows the final balance and interest.
You can compare up to three offers at once. The best highlighted row has the highest APY. A longer CD can show more total interest, so the per-month column helps you compare terms of different lengths.
Quick explanation: Final balance = deposit × (1 + APY) ^ (months ÷ 12).
- APY: the yearly return, including compounding.
- Term: how long the money stays in the CD, in months.
- Tax rate: optional, used to estimate interest after tax.
Core Formulas
- Final balance: FV = P × (1 + APY) ^ (m ÷ 12)
- Interest: I = FV − P
- After-tax interest: I × (1 − tax rate)
P is your deposit, APY is written as a decimal, and m is the term in months. Because APY already includes compounding, you do not need to enter how often the bank compounds.
Worked Example
You deposit $10,000 for 24 months at 4.25% APY.
- Final balance = 10,000 × 1.0425 ^ 2 = $10,868.06
- Interest = $868.06
- Interest per month = about $36.17
Things to Check Before You Choose
- Early withdrawal penalty: taking money out early can cost part of the interest. Check the terms first.
- Automatic renewal: many CDs renew at maturity unless you act during the grace period.
- Deposit insurance: check that the bank or credit union is insured, and stay within the limits.
- Inflation: interest may buy less in the future. Try our Inflation Calculator.
Frequently Asked Questions
CD interest comes from your deposit, rate and term. With APY, the final balance is the deposit multiplied by (1 + APY) raised to the term in years.
The interest rate is the stated rate before compounding. APY includes compounding, so it shows the real yearly return and is better for comparing offers.
At 4.50% APY for 12 months, $10,000 earns $450. Enter your own rate and term above to see your result.
No. A longer CD can earn more in total, but your money is locked in for longer. Compare the APY, the term and any early withdrawal penalty.
In the US, CD interest is generally taxable in the year it is earned. Enter a tax rate above for an estimate, and check your own situation with a tax professional.
References & Sources
| Source | Used For | Link |
|---|---|---|
| Consumer Financial Protection Bureau, Regulation DD (Truth in Savings) | Definition of annual percentage yield. | https://www.consumerfinance.gov/rules-policy/regulations/1030/ |
| U.S. SEC, Investor.gov compound interest guide | How money grows with compounding. | https://www.investor.gov/financial-tools-calculators/calculators/compound-interest-calculator |