Navigation
🏠 Home🧮 All Tools 🏡 Mortgage 📅 Amortization

📈 Interest Calculator

Calculate simple interest and compound interest. See exactly how your savings or debt grows over time.

📐Simple Interest
%
Principal
Simple Interest
Total Amount
📈Compound Interest
%
yrs
Principal
Compound Interest Earned
Total Amount
Effective Annual Rate

Simple Interest Formula

SI = (Principal × Rate × Time) / 100. Total = Principal + SI. Simple interest is calculated only on the original principal amount.

Compound Interest Formula

A = P × (1 + r/n)^(n×t). Where P = principal, r = annual rate, n = compounding frequency per year, t = time in years. Compound interest grows faster because interest is added to the principal each period.

Simple vs Compound Interest

Compound interest is significantly more powerful over long periods. For example, ₹1 lakh at 8% for 20 years: Simple Interest gives ₹2.6 lakh, while Compound Interest (quarterly) gives ₹4.87 lakh — nearly double!

When is Each Used?

  • Simple Interest: Short-term loans, car loans, some savings accounts
  • Compound Interest: FDs, mutual funds, long-term investments, home loans