Free online CD calculator

How to use

1. Enter the principal — the amount you plan to deposit.
2. Enter the APY as shown on the bank’s CD offer.
3. Set the term in months (12 = 1 year, 60 = 5 years).
4. Choose the compounding frequency (monthly is most common).
5. The calculator instantly shows final balance, total interest, and a month-by-month table.

The formula

Final Balance = P × (1 + APY / 100)^(t / 12)
Interest = Final Balance − P

Where:

• P = principal ($)
• APY = Annual Percentage Yield (%)
• t = term in months

Because APY already accounts for compounding, this formula gives the correct result regardless of how often the bank compounds internally.

Worked example

You deposit $10,000 in a 12-month CD at 5.00% APY:

• Final Balance = $10,000 × (1 + 0.05)^(12/12) = $10,000 × 1.05 = $10,500.00
• Interest earned = $10,500.00 − $10,000 = $500.00

A 24-month CD at 5.5% APY with $10,000:

• Final Balance = $10,000 × (1.055)^2 = $10,000 × 1.113025 = $11,130.25
• Interest = $1,130.25

Notes

• CDs are FDIC-insured up to $250,000 per depositor, per bank.
• CD rates are typically higher than standard savings accounts because you commit to leaving funds untouched.
• The month-by-month table shows up to 24 months; for longer terms the final month is also shown.
• This calculator does not model early withdrawal penalties or taxes on interest income.