WiseCalc

CD Interest Calculator

Estimate USD CD growth using entered APY and term assumptions, with explicit cent rounding and excluded fees.

Entered constant APY assumption, including compounding: USD deposit × (1 + APY / 100)^(months / 12). Interest stays invested. Months are twelfths of a year; fractional-month values are numerical estimates. Actual bank crediting depends on dates and account terms. Taxes, fees and early-withdrawal penalties are excluded.

$
$0$500,000
%
0%10%
months
0months60months

Deposit rounds to cents first, half up. Interest rounds to cents, half up; maturity equals rounded deposit plus rounded interest. A positive interest amount below half a cent is also shown before rounding in approximate scientific USD. Monthly average is interest divided by elapsed months, not a payout.

Entered USD deposit; APY percent; term months: 10000; 5; 12

Rounded USD starting amount: $10,000.00

Maturity Value
$10,500.00
Total Interest
$500.00
Term Return
5.000%
Avg Monthly Interest
$41.67
Average over elapsed months; not a monthly payout.
Rounded USD balances at shown month marks
MonthDeposit AmountCD Value
0$10,000.00$10,000.00
1$10,000.00$10,040.74
2$10,000.00$10,081.65
3$10,000.00$10,122.72
4$10,000.00$10,163.96
5$10,000.00$10,205.37
6$10,000.00$10,246.95
7$10,000.00$10,288.70
8$10,000.00$10,330.62
9$10,000.00$10,372.70
10$10,000.00$10,414.96
11$10,000.00$10,457.40
12$10,000.00$10,500.00

Chart positions use proportional elapsed months. Balance marks are samples; interest and totals use the entire modeled term.

CD Growth Over Term

USD balance: start / end

  • CD Value: $10,000.00 / $10,500.00
  • Deposit Amount: $10,000.00 / $10,000.00

Inputs and APY

Deposit is the one-time starting amount; term is measured in months. Enter advertised APY, which includes compounding, rather than a nominal interest rate. This page does not model additional deposits.

Worked example: a 12-month CD

Enter $10,000, 5% APY and 12 months: maturity value is $10,500.00 and total interest is $500.00. The average monthly interest is $41.67; it is an average, not a promised monthly payout.

With the same deposit and APY for 6 months, $10,000 × 1.05^(6/12) = $10,246.95, earning $246.95. Half a year uses fractional-power growth, not simply half the annual yield.

What the estimate includes

The formula is deposit × (1 + APY/100)^(months/12). APY is held constant and interest stays in the account. Each month is one twelfth of a year, including fractional terms. Taxes, fees and early-withdrawal penalties are excluded. Calendar dates, payout timing and account terms can change the bank result; check the account disclosure.

When to use another calculator

For regular contributions and a nominal annual rate, use the compound interest calculator. It uses a different rate definition, so do not copy an APY into its nominal-rate field without conversion.

Rounded USD starting amount

Entered constant APY assumption, including compounding: USD deposit × (1 + APY / 100)^(months / 12). Interest stays invested. Months are twelfths of a year; fractional-month values are numerical estimates. Actual bank crediting depends on dates and account terms. Taxes, fees and early-withdrawal penalties are excluded.

Deposit rounds to cents first, half up. Interest rounds to cents, half up; maturity equals rounded deposit plus rounded interest. A positive interest amount below half a cent is also shown before rounding in approximate scientific USD. Monthly average is interest divided by elapsed months, not a payout.

Zero elapsed months: interest is zero; the monthly average is undefined. The chart shows only the starting balance.

Zero deposit: interest is zero; investment return has no invested basis.

A positive deposit or principal rounds to zero cents. Enter at least half a cent, or zero. Results and PDF are unavailable at this resolution.