Simple & Compound Interest Calculator Simple & Compound Interest Calculator Calculator Principal Amount Annual Interest Rate (%) Time (Years) Compounding Annually Semi-Annually Quarterly Monthly Daily Calculate Simple Interest: Simple Amount: Compound Interest: Compound Amount: Difference: Growth Graph Difference Between Simple and Compound Interest Feature Simple Interest Compound Interest Formula P×R×T/100 P(1+r/n) nt Interest On Principal Only Principal + Previous Interest Growth Linear Exponential Best For Loans Investments Returns Lower Higher Over Time Formulas Simple Interest: SI = (P × R × T) / 100 Compound Amount: A = P(1 + r/n) nt FAQs What is Simple Interest? Simple interest is calculated only on the original principal. What is Compound Interest? Compound interest earns interest on both the principal and previously earned interest.