Side-by-side comparison showing the power of compounding year by year.. Simple vs Compound Interest is a free online tool from the ToolsRift Finance & Health Calculators collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.
Enter your principal, interest rate and number of years. The calculator shows simple and compound interest side by side with a year-by-year comparison table.
Simple interest is charged only on the original principal, while compound interest is charged on principal plus accumulated interest, so it grows faster over time.
Simple interest = P × r × t. Compound interest gives A = P × (1 + r)^t. The gap between them widens the longer the money stays invested.
Over long periods and at higher rates. Early years look similar, but compounding pulls far ahead the longer you stay invested, which is why time is so valuable.