Compound Interest

Use this calculator to see how a starting amount and steady monthly investing may grow over time. It is useful for setting realistic expectations, comparing different contribution habits, and checking how much patience matters. The result is a simple illustration, not a prediction, so it is still worth testing a few return assumptions instead of relying on one number.

Initial amountMonthly contributionAnnual return %

Advanced

All-in annual drag % (fees)Tax drag %/year (approx)Contribution increase %/year

Years

Yearly breakdown (CSV)

Assumptions

Constant return compounded monthly (illustration).
Contributions are added at the start of each month.
Net return is approximated as (return − drag − tax drag). If you set contribution growth, monthly contributions increase once per year.
Does not include taxes, broker fees, or ETF TER.