Tools / Compound Interest Calculator

Compound Interest Calculator

Calculate investment growth with compound interest. See how your money grows over time with different rates and contribution schedules.

7,200 AI Tokens Used
Feb 1, 2026 Created
financecalculator
Categories
$
%
years
$
Final Balance$37,506
Initial Investment$10,000
Total Contributions$22,000
Total Interest Earned$15,506
Interest Rate7% / year
Contributions (58.7%)
Interest (41.3%)
Compound Interest Formula

A = P(1 + r/n)nt where P = principal, r = annual rate, n = compounds per year, t = years. With regular contributions, future value is calculated using the annuity formula.

All calculations happen locally in your browser. Results are estimates for educational purposes.

How This Tool Was Built

This tool was created entirely by AI. Here's the exact prompt used to generate it:

Prompt Used 
Create a Compound Interest Calculator tool with these features:

1. Inputs:
   - Initial investment (principal)
   - Annual interest rate
   - Time period in years
   - Monthly contribution (optional)
2. Compound frequency options: annually, semi-annually, quarterly, monthly, daily
3. Results showing:
   - Final balance (large, prominent)
   - Total contributions
   - Total interest earned
   - Visual breakdown bar (contributions vs interest)
4. Year-by-year breakdown table (toggleable)
5. Use formula A = P(1 + r/n)^(nt)
6. Handle monthly contributions with future value of annuity formula

Make it professional with green as the accent color. Include educational info about the formula.
AI
Claude AI Model
#
7,200 Tokens Used
100%
AI-Generated Code Origin