Free Tool
Simple and Compound Interest Calculator
Compare simple interest and compound interest for any principal, rate and time.
Enter principal, rate and time
Interest formulas
- Simple interest = (P × R × T) ÷ 100.
- Compound amount = P × (1 + R ÷ (100 × n))n×T, where n is the number of compounding periods per year.
- Compound interest = Amount − Principal.
Quick fact
For the first year, simple and compound interest (yearly compounding) are equal. The difference grows each year.
Practise more in our maths practice paper.