Compound interest rewards time more than money. Watch what your savings become — and see the real price of every year you put it off, because the years you skip are the most powerful ones you'll ever have.
The growth engine. Your starting amount compounds at the annual return you set, and each period you add your contribution, which then compounds too. The math is the standard future-value-of-a-series formula, applied at your chosen compounding frequency. Contributions can grow each year if you set a contribution-growth rate.
Contributions vs. growth. The chart splits your balance into two bands: the money you actually put in (your contributions) and everything earned on top of it (compound growth). Early on, the balance is almost all contributions. Later, growth takes over and dwarfs what you put in — that crossover is the whole magic of compounding.
The cost of waiting. Starting later means fewer years of compounding — and because the earliest years are the ones with the longest runway, they're worth the most. The calculator runs the same plan starting today versus starting after a delay, and the difference in final balance is what the delay costs you. The price-of-delay table shows this for one through several years.
Returns are assumed steady; real markets bounce around year to year. Figures are in nominal dollars and don't subtract inflation or taxes — to see growth in today's buying power, mentally knock a few points off the return rate.