Watch interest start earning its own interest.
Compounding is monthly here: each month the balance earns rate ÷ 12, and your contribution lands on top. The split line is the instructive part — over long horizons, interest quietly overtakes deposits. This is an illustration with a fixed rate; real investments vary year to year, which changes the path (though not the principle).
Why does starting early matter so much? Compounding is exponential: growth feeds growth. A decade’s head start can outweigh doubling the monthly amount later — try both scenarios and compare the split.
Does this include taxes or inflation? No — it’s the raw growth math. Inflation quietly subtracts roughly its own percentage from the "real" return.