CD maturity value calculator

Formula and example

The periodic rate equivalent to an entered effective annual yield is r_p = (1 + APY)^1/m − 1, where m is the selected number of compounding periods per year. For a term of y years, the modeled balance is P × (1 + r_p)^{m × y}; modeled interest is the balance minus the starting deposit P. Because APY already reflects compounding over a year, changing the frequency changes the equivalent periodic rate shown but does not change the annual yield implied by the APY.

For example, a $10,000 deposit at 4.00% APY for 12 months gives a modeled maturity balance of $10,400 and $400 interest before any excluded costs. This is a calculation from the displayed assumptions, not an offer or a rate quote.

The FDIC describes APY as reflecting both the interest rate and the frequency of compounding over a 365-day year, or 366 days in a leap year. Its Truth in Savings guidance also describes disclosures for time accounts, including compounding and crediting frequency, early-withdrawal penalties, and maturity or renewal terms. Source checked November 3, 2026: FDIC Consumer Compliance Examination Manual: Truth in Savings.

This simplified model treats the entered APY as fixed for the full term and assumes no additional deposits or withdrawals. It does not model the bank's day-count method, leap-day treatment, daily accrual details, rounding, fees, taxes, early-withdrawal penalties, or automatic renewal. The account disclosure and maturity notice control actual terms and amounts. Confirm the APY, compounding and crediting schedule, penalty, and maturity instructions with the institution. This is an educational estimate, not individualized financial advice.

Related savings tools

For a savings balance with recurring deposits and user-entered return and fee assumptions, use the compound savings planner. To compare simple interest with a fixed nominal-rate compounding scenario, use the interest calculator.

How it works

Enter the deposit amount, the account's disclosed APY, term in months, and compounding frequency. The calculator converts APY to an equivalent periodic rate and estimates the balance at maturity.