FinanceCalc

CD Interest Calculator

Calculate how much interest you'll earn on your CD investment. See total interest earned, effective APY, and monthly interest breakdown.

CD Details

$100.00$1,000,000
0.10%10.00%

Total: 12 months (1.0 years)

0.00%50.00%
0.00%10.00%
Total Interest Earned
$512.67
After Tax Interest
$399.89
Total Value at Maturity
$10,512.67
After Tax Value
$10,399.89
Real Interest (Inflation-Adjusted)
$512.67
Real Value (Inflation-Adjusted)
$10,512.67

Principal vs Interest

Interest Growth Over Time

Monthly Interest Breakdown

MonthMonthly InterestCumulative InterestTotal Value
1$41.75$41.75$10,041.75
2$41.93$83.68$10,083.68
3$42.10$125.78$10,125.78
4$42.28$168.05$10,168.05
5$42.45$210.50$10,210.50
6$42.63$253.13$10,253.13
7$42.81$295.94$10,295.94
8$42.99$338.93$10,338.93
9$43.17$382.09$10,382.09
10$43.35$425.44$10,425.44
11$43.53$468.97$10,468.97
12$43.71$512.67$10,512.67

What is CD Interest?

CD interest is the return you earn on your certificate of deposit investment. Unlike simple interest, most CDs use compound interest, which means you earn interest on both your initial principal and previously earned interest.

Our CD interest calculator helps you understand exactly how much interest you'll earn, how it accumulates over time, and the impact of different compounding frequencies.

How CD Interest is Calculated

CD interest is calculated using the compound interest formula:

Interest = P(1 + r/n)^(nt) - P

Where:

P = Principal (initial deposit)

r = Annual interest rate (APY)

n = Compounding frequency per year

t = Time period in years

Our CD interest calculator automatically handles this calculation and shows you the breakdown month by month.

Simple vs Compound Interest on CDs

Most CDs use compound interest, which is more beneficial than simple interest:

Compound Interest

  • Earn interest on interest
  • Higher total returns
  • Used by most CDs
  • Compounds daily, monthly, or quarterly

Simple Interest

  • Only earns on principal
  • Lower total returns
  • Rarely used for CDs
  • Fixed calculation

How Compounding Frequency Affects Interest

The frequency of compounding significantly impacts your total interest earned:

  • Daily Compounding: Interest calculated every day - highest returns
  • Monthly Compounding: Interest calculated monthly - good returns
  • Quarterly Compounding: Interest calculated every 3 months - moderate returns
  • Annual Compounding: Interest calculated once per year - lowest returns

Use our CD interest calculator to see the exact difference between compounding frequencies for your investment.

Tips to Maximize CD Interest

1. Choose Higher Rates

Even a 0.5% difference can significantly impact your total interest earned over time.

2. Opt for Daily Compounding

Daily compounding yields the highest returns, though the difference from monthly is usually small.

3. Consider Longer Terms

Longer-term CDs typically offer higher interest rates, resulting in more total interest earned.

4. Understand Tax Implications

CD interest is taxable as ordinary income. Use our calculator's tax feature to see your after-tax returns.

Frequently Asked Questions