Free online calculator · Financial
Investment Growth Calculator
Estimate how an initial investment and recurring monthly contributions may grow with compound returns. Market returns are not guaranteed.
Formula • Worked example • Interpretation
Project savings with recurring contributions
Investment growth estimates combine an initial balance, repeated additions, a hypothetical return, and time. They help explain compounding, not predict market performance.
Calculation method
With monthly compounding, starting principal grows as P(1+r)ⁿ. End-of-month additions A contribute A × ((1+r)ⁿ − 1) / r, where r is monthly return and n is months.
Worked example
Starting with $1,000 and adding $100 at the end of every month for ten years produces $13,000 in contributions and starting principal before investment growth. A positive assumed return increases the projected balance.
What your result means
Separate what you contributed from growth due to the assumed return. Try more conservative and optimistic rates instead of assuming one rate will occur each year.
Tips for better calculations
For a fair scenario comparison, hold monthly contributions and time constant while adjusting just the annual return.
Assumptions and limitations
Returns are hypothetical, not guaranteed. Market volatility, taxes, investment fees, inflation and contribution timing may change actual results.
SiCalcs tools provide estimates and educational calculations; they do not replace professional financial, medical, tax, or legal advice.