CD maturity calculator
Estimate a certificate of deposit at maturity.
- Formula and assumptions shown
- Table and CSV export
- Runs in your browser
How it works
A certificate of deposit is modeled here as one starting deposit that remains invested for a fixed term. The calculator compounds the entered rate and does not add recurring deposits.
Maturity = deposit × (1 + annual rate ÷ periods)^(periods × years).
The maturity estimate helps compare term and rate assumptions. Actual certificates can have renewal rules, early-withdrawal penalties, or taxes that are outside this model.
Assumptions
- The starting deposit is the only contribution.
- The entered nominal rate and compounding frequency stay fixed until maturity.
- Interest remains in the certificate and compounds at the selected frequency.
- Early-withdrawal penalties, taxes, and renewal terms are not modeled.
Worked example
$5,000 for one year
At a 4% nominal rate compounded monthly, the estimate is $5,000 × (1 + 0.04/12)^12 = about $5,203.71, including $203.71 of interest.
Step by step
- Count the compounding periods. A 12-month term with monthly compounding has 12 ÷ 12 × 12 = 12 periods.
- Find the rate per period. 4% ÷ 12 = 0.3333% per month (0.0033333 as a decimal).
- Compound over the term. (1 + 0.0033333)^12 = 1.040742, so each dollar grows to about $1.0407 by maturity.
- Apply it to the deposit. $5,000 × 1.040742 = $5,203.71 maturity value.
- Subtract the deposit for interest. $5,203.71 − $5,000 = $203.71 of interest, a 4.0742% return over the year, which is the APY of a 4% rate compounded monthly.
How to read your result
Maturity value is what the certificate is worth at the end of the term if the deposit and all credited interest stay in the account. Interest earned is maturity value minus the deposit, and Term repeats the months you entered. The bar chart and table show deposit, interest, and maturity value on one dollar scale.
Terms that are not whole years work the same way: an 18-month CD with quarterly compounding has 6 periods, and $5,000 at 4% grows to $5,307.60. If a bank quotes only an APY, a one-year CD’s interest is simply deposit × APY, so a 4.0742% APY on $5,000 gives the same $203.71.
The estimate assumes the money stays in until maturity. It does not model early-withdrawal penalties, taxes on interest, interest paid out instead of compounded, or what happens at renewal, when many CDs roll into a new term at whatever rate applies then.
What changes the result most
- Term
- Doubling the term to 24 months at 4% gives $5,415.71, which is $415.71 of interest, slightly more than twice the one-year $203.71 because the second year earns on the first year’s interest. A 60-month term reaches $6,104.98.
- Rate
- A 4.5% rate instead of 4% raises the one-year maturity value to $5,229.70, which is $25.99 more interest on $5,000.
- Compounding frequency
- Frequency matters little at these amounts: at 4% for one year, daily compounding gives $5,204.04, monthly $5,203.71, and annual $5,200.00.
Questions
Can I add monthly deposits?
This tool treats the CD as a single fixed deposit. Use a savings or compound-growth calculator for recurring contributions.
Does the result include an early-withdrawal penalty?
No. This model has no penalty field. Check the certificate agreement because early-withdrawal terms vary by provider and account.
Is the entered rate an APY?
The model expects a nominal annual rate and a compounding frequency. If you have APY, convert it or use the provider's stated maturity value.
Are CDs worth it?
It depends on what the money is for. A CD fixes the rate for the term, and deposits at FDIC-insured banks are insured up to $250,000 per depositor, per bank, per ownership category. In exchange, the money is committed until maturity, and taking it out early usually costs a penalty. Comparing the CD’s maturity value with a liquid savings account at its current rate, and with expected inflation, shows the trade-off in dollars.
How are CD early withdrawal penalties calculated?
The account agreement sets the penalty, and it is often stated as a number of days or months of interest. Federal Regulation D sets a minimum of seven days’ simple interest for money withdrawn within six days of deposit. As an illustration, a penalty of three months’ simple interest on $5,000 at 4% would be $5,000 × 0.04 × 3 ÷ 12 = $50.
Is CD interest taxable?
In the United States, interest on CDs and other bank deposits is generally taxable income. The IRS (Topic No. 403, Interest received) says payers issue Form 1099-INT when they pay $10 or more of interest. This calculator shows interest before any tax.
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Sources
These references explain the concepts behind the calculation. They do not endorse this site. Estimates leave out any cost or condition you did not enter.