← Back to all toolsMathematics · Class 7–10
Simple & Compound Interest
Enter the principal, rate and time to compare Simple Interest and Compound Interest side by side — with a bar chart, yearly table and full working.
SI= (P × R × T) / 100
CI= P(1 + R/n·100)^nT − P
Quick examples:
Currency symbol
₹
% p.a.
years
💡 Simple Interest
- Interest is calculated only on the original principal
- SI = (P × R × T) / 100
- Interest is the same every year — it grows linearly
- Used for: short-term loans, vehicle loans
📈 Compound Interest
- Interest is added to principal at each compounding period
- A = P(1 + R/n·100)^(nT)
- Growth is exponential — "interest on interest"
- Used for: bank FDs, savings accounts, investments
🔑 Key Differences
- CI always earns more than SI for the same P, R, T
- The gap between CI and SI widens each year
- More frequent compounding → higher CI
- For Class 10: CI − SI = P(R/100)² for 2 years