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CD Interest Calculator

Enter deposit, APY, term, and optional penalty → Get projected CD interest and ending balance.

Calculate CD Interest from APY

Comparing maturity value with an early-withdrawal scenario? Enter the quoted APY, deposit, term, and any stated penalty.

Your CD interest estimate will appear here
Enter a deposit, APY, and term; results update automatically.

This is a projection, not a bank quote. APY, withdrawal rules, penalty calculation, rounding, taxes, and renewal terms vary by institution. Confirm the account disclosure before depositing or withdrawing.

How to Use CD Interest Calculator

1

Enter the Opening Deposit

Use the principal that will remain in the CD without additional contributions.

2

Add the Quoted APY and Term

Copy the APY from the account disclosure and enter the term in months.

3

Model an Optional Penalty

Enter months of interest only when the bank describes its penalty that way.

4

Review the Live Projection

Compare maturity value, earned interest, and the penalty-adjusted planning balance.

CD Interest Calculator Features

  • Correct APY-based growth without double-counting compounding
  • Terms from 1 to 120 months
  • Separate maturity value, interest, and penalty-adjusted balance
  • Live results with the active formulas shown

Common Use Cases

Compare certificate of deposit offers

Apply each bank’s quoted APY and term to the same deposit before comparing liquidity and penalty terms.

Estimate an early withdrawal

Enter the stated months-of-interest penalty for a rough balance, then verify the bank’s actual calculation.

Limits and Important Notes

How the CD Interest Calculator Works

APY represents annual growth after compounding. The calculator raises one plus APY to the term in years and multiplies by the opening principal.

The optional penalty is estimated as simple interest on the original principal for the entered number of months.

Formula

Maturity = principal × (1 + APY)^(months ÷ 12); penalty estimate = principal × APY × penalty months ÷ 12

Example

A $10,000 deposit at 4.50% APY for 12 months grows to $10,450.00 and earns $450.00. A three-month simple-interest penalty estimate is $112.50, leaving $10,337.50.

  • Actual APY, daily accrual, maturity dates, rounding, and renewal rules come from the bank’s disclosure.
  • The penalty model may not match a bank that uses earned interest, current balance, minimum days, or principal forfeiture.
  • Income tax, inflation, fees, insurance limits, rate changes on variable products, and additional deposits are excluded.

Frequently Asked Questions