See the power of compounding on your savings and investments
Compound interest has been called the eighth wonder of the world, and for good reason: it lets your money earn returns not just on what you originally invested, but on the returns it has already generated. Over years and decades this snowball effect can turn modest, consistent saving into a substantial sum. Our free compound interest calculator makes that abstract idea concrete by projecting exactly how a starting balance grows given your rate, time horizon, and contribution habits.
The tool goes beyond a single lump-sum projection. You can add a regular monthly contribution, which is how most people actually save, and choose how often interest compounds — annually, quarterly, monthly, or daily. Each of these levers changes the outcome, and the calculator reflects them instantly. It separates your total contributions from the interest earned so you can clearly see how much of your final balance came from your own deposits versus the compounding effect working on your behalf.
To make the growth tangible, a year-by-year table charts your balance at the end of every year, showing contributions and accumulated interest at each stage. This helps you understand the shape of compounding: growth is slow at first and accelerates over time, which is exactly why starting early matters so much. Use the calculator to set savings goals, compare scenarios, and stay motivated — while remembering that real-world returns fluctuate and are never guaranteed.