CD calculator
Estimate a certificate of deposit’s maturity balance, interest, APY and an optional early-withdrawal outcome.
CD calculation formulas
When APY is entered, the balance after t years is A = P × (1 + APY)t. When a nominal annual rate is entered and interest compounds n times per year, A = P × (1 + r ÷ n)n × t.
The calculator converts a nominal rate to APY with APY = (1 + r ÷ n)n − 1. If APY is supplied, the equivalent nominal rate is r = n × ((1 + APY)1/n − 1).
The optional penalty estimate is P × equivalent nominal rate × penalty months ÷ 12. This is only an estimate: the actual penalty basis, minimum penalty and treatment of principal are controlled by the deposit agreement.
Example
A $10,000 CD with a 4.50% APY and a 12-month term reaches $10,450.00, earning $450.00. A withdrawal after six months has about $222.50 of accrued interest before any penalty. Exact bank posting and day-count rules can create small differences.
What this calculator includes
- APY or nominal annual interest rate input.
- Daily, monthly, quarterly, semiannual or annual compounding.
- Terms from one to 600 months.
- Optional early-withdrawal month and editable penalty.
- Milestones through maturity, including partial final years.
Limits and assumptions
This calculator assumes a fixed rate and no additional deposits. It does not model callable, bump-up, step-rate, brokered, market-linked or variable-rate CDs. It excludes taxes, fees, deposit-insurance limits and bank-specific day-count conventions. Results are estimates, not an offer or financial advice.
Related calculators
- Compound Interest Calculator — model recurring contributions and longer-term growth.
- Retirement Calculator — estimate long-term savings needs and contributions.
Compare yield conventions: Use the APY Calculator to convert nominal APR and APY or derive annual yield from two balances.