Financial Calculators
CD Calculator
Estimate certificate of deposit earnings, APY, and early withdrawal penalties from deposit amount, rate, and term locally in your browser.
Enter a deposit amount, APY, and term to estimate CD earnings. Optionally add an early withdrawal month to see the penalty impact. This calculator runs privately in your browser; your numbers are not uploaded or stored.
Penalty estimate assumes 3 months' simple interest on the principal; actual penalties vary by institution.
See what a CD could earn before you commit.
Enter a deposit amount, APY, term in months, and compounding frequency to estimate the maturity value and total interest. Optionally add an early withdrawal month to see the estimated penalty impact using a common 3-month simple interest penalty. Actual penalties vary by institution. This private browser estimate is for general planning only, not financial advice; your values are not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
What formula does the CD calculator use?
It uses compound interest: maturity value = deposit × (1 + APY / 100 / n)^(n × years), where n is the compounding periods per year. The APY shown is the effective annual yield: (1 + periodic rate)^n − 1. The early withdrawal penalty estimates 3 months of simple interest on the principal.
How does the early withdrawal penalty work?
Many banks charge a penalty of 3 months of simple interest on the principal for early withdrawal. The calculator shows the balance before penalty, the estimated penalty, and the net amount. Actual penalties vary by institution and term length, so check your CD agreement.
What compounding frequencies are supported?
Annually, semiannually, quarterly, monthly, and daily. More frequent compounding produces a slightly higher effective yield for the same APY.
Do my values stay private, and is this financial advice?
Yes. The calculation and copy action run locally in your browser. CodeASystem does not upload or store the values you enter. This is a general planning estimate, not financial advice.