Compound Growth Calculator
Final value from initial amount, monthly savings and return.
Also available in German: Zinseszins-Rechner →
Inputs
Discount / required rate
Also called: Required return, hurdle rate
Where to find it: Your own required return — or via CAPM (discount-rate calculator).
How to derive: Risk-free rate + beta × market premium. Equities typically 7–10%.
Result, live
Monthly compounding, end-of-month contributions. Not inflation-adjusted.
The compound growth calculator shows what your initial amount plus a monthly contribution turns into over the years. It reinvests every month, so your returns start earning returns of their own. You instantly see how time and rate of return work together.
How the formula works
The final value has two parts: your initial amount compounded, plus every contribution compounded from the month you pay it in. It runs monthly, using a monthly rate of r = return ÷ 12.
Example: $10,000 up front plus $200 a month at 7% p.a. over 20 years grows to about $144,573. You only paid in $58,000 – the other ~$86,573 is pure compounding.
How to read the result
- Final value – what you end up with on paper, including all growth.
- Total contributions – the money you actually paid in (start + every deposit).
- Growth – the difference, i.e. the pure compounding effect.
- The longer the horizon, the more sharply the curve bends upward near the end.
What to watch out for
- The return is an assumption, not a promise – real markets swing from year to year.
- Inflation is not included: $144,573 in 20 years buys less than it does today.
- Tax on interest and gains plus account fees will lower the real outcome.