Why a Compound Interest Chart Should Simulate Contributions Period by Period
javascript
dev.to
A compound-interest formula can give you a final number quickly, but it can also hide whether deposits happen monthly, annually, or not at all. I built the calculator around a small simulation loop so the chart and yearly table explain where the final balance came from. Normalize the inputs before doing finance math The computed result converts the form values and clamps the horizon: const P = Number(principal.value) || 0; const r = (Number(annualRate.value) || 0) / 100; const Y =