What is compound interest?
Compound interest means you earn interest not only on your original deposit, but also on the interest already added. Over time this snowballs — which is why starting early matters so much.
Future value = Principal × (1 + rate)years
The cost of waiting
Because growth compounds, a few extra years at the start can outweigh a much larger deposit later. Try changing the number of years and watch how the interest earned grows far faster than the deposit itself.
Assumes a fixed annual rate compounded yearly with no withdrawals or extra deposits. Real returns vary.