Personal Finance • Wealth Accumulation

Compound Interest & Investment Growth Calculator

Forecast how principal and regular monthly contributions compound into financial freedom over 5 to 40 years.

100% Free Online Real-Time Calculations Client-Side Privacy Guaranteed

Compound Interest & Investment Growth Calculator

Interactive Calculation Console

How This Calculator Works

Where P is starting principal, r is annual return rate, n is compounding frequency, t is time in years, and PMT represents monthly contribution.

Compound Interest Formula

A = P(1 + r/n)^(nt) + PMT × [((1 + r/n)^(nt) - 1) / (r/n)]

Frequently Asked Questions

What is the Rule of 72?
Divide 72 by your expected annual return percentage to approximate how many years it will take for your money to double (e.g. at 8% return, 72 / 8 = 9 years).
Does compounding frequency make a large difference?

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