How growth builds on growth
Compounding means each year's growth is worked out on everything so far, including past growth. Time matters as much as the rate. Try your own numbers and a few different returns.
Nobody knows future returns. Try a few values, including low and negative ones.
How this is worked out: monthly compounding at (yearly return ÷ 12), with each month's addition going in at the end of the month. The same return is used every year.
Real returns go up and down from year to year, and some years lose money. Fees, taxes and rising prices are not included. To see what a fee takes from this, try Fund fees.