CD Calculator
Calculate your exact certificate of deposit earnings, compound interest growth, and after-tax return based on standard US banking formulas.
Deposit Parameters
Most major US online banks (Ally, Marcus, Capital One) compound daily.
CD interest is taxed at ordinary federal income rates.
Deposit is fully within the $250,000 FDIC single-account coverage limit.
Compound Growth Schedule
Estimated timeline| Period | Starting Principal | Interest Earned | Ending Balance |
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Balance Growth Trajectory & Forecast
Live ChartWidescreen trajectory visualization comparing guaranteed principal against compounding interest
Frequently Asked Questions
Everything you need to know about US Certificate of Deposit calculations.
What is the formula used in this CD Calculator?
This calculator uses the standard compound interest formula: A = P(1 + r/n)^(n*t), where A is the final balance, P is the principal deposit, r is the annual nominal interest rate derived from APY, n is the compounding frequency (daily = 365, monthly = 12), and t is time in years.
How does APY differ from interest rate?
Interest rate is the base percentage earned on your money before compounding. APY (Annual Percentage Yield) reflects the total amount of interest you actually earn over one full year, taking compounding frequency into account. APY is always equal to or slightly higher than the nominal interest rate.
Are CD interest earnings subject to US federal income tax?
Yes, in the United States, interest earned on certificates of deposit is considered taxable ordinary income by the IRS for the tax year in which it is credited to your account, even if you do not withdraw the money until maturity. Banks issue Form 1099-INT if you earn $10 or more in interest.
Is my deposit safe in a US CD?
Yes, as long as your CD is held at an FDIC-insured commercial bank or NCUA-insured credit union, your deposit is backed by the full faith and credit of the United States government up to $250,000 per depositor, per institution.