Tool: CD calculator · Embed: Embeddable CD calculator · All how-we-calculate pages · CD questions
Purpose
The CD calculator estimates certificate of deposit maturity value and interest for education. It is not a bank quote, Truth in Savings disclosure, or personalized advice. U.S. deposit products offered by covered institutions must follow Regulation DD (Truth in Savings, 12 CFR Part 1030); our tool does not replace those disclosures.
Discrete compounding
A = P × (1 + r/n)^(n×t)
- P — principal
- r — annual nominal rate (decimal)
- n — periods per year (365 daily, 12 monthly, 4 quarterly, 2 semi-annual, 1 annual)
- t — years (term months ÷ 12)
Continuous compounding
A = P × e^(r×t)
Continuous compounding is the mathematical limit of more frequent discrete compounding. It is included for completeness; many retail CDs use discrete schedules.
APY input conversion
When you enter APY, we convert it to a nominal rate consistent with the selected compounding so that, under this model, a one-year horizon matches the entered APY:
- Discrete:
r = n × ((1 + APY)^(1/n) − 1) - Continuous:
r = ln(1 + APY)
Example: at 4.50% APY for one year with no fees, $10,000 grows by $450 to $10,450 under a pure 4.50% effective annual yield—arithmetic under stated assumptions, not a claim about any bank’s current rates.
Optional monthly deposits
If you add a monthly deposit, we simulate month-by-month growth then add the deposit. Many traditional CDs do not allow add-on deposits; treat this mode as a planning illustration only.
Outputs
- Final balance, interest earned, total deposited, effective APY under the model
- Growth chart and period schedule
- Compare common terms table
- Copy results and browser PDF export
- Share, embed, and URL prefills
What we intentionally omit
- Early withdrawal penalties
- Promotional or step-up rates
- Account fees and minimums
- Tax withholding or tax advice
- Issuer-specific day-count rules
Primary external references
- CFPB — Regulation DD (Truth in Savings)
- CFPB — What is a CD?
- FDIC — Deposit insurance
- NCUA — Share insurance
Related content
Last reviewed: July 22, 2026.
YMYL notice: This site is for education only. It is not financial, tax, or investment advice. Nestfigure is not a bank, credit union, broker, investment adviser, or fiduciary. Product terms, rates, and penalties vary—always read your institution’s disclosures before acting. Calculator results are mathematical estimates, not bank quotes.