Recurring Investment Calculator
Project the maturity value of a fixed monthly investment: total invested, wealth gain and growth year by year.
How it works
Each month: value = value × (1 + r) + investment, where r = annual return ÷ 12
A fixed amount invested every month compounds into a maturity value made of two parts: the money you put in and the growth it earns. Early contributions have the most time to compound, so they do the heaviest lifting — which is why starting sooner matters more than investing more later. The wealth gain is simply the maturity value minus everything you contributed.
Worked example
Investing $500 a month for 15 years at an 8% return grows to about $173,019. You contribute $90,000 over the period, so roughly $83,019 of the total is investment gain.
Frequently asked questions
Is the contribution added before or after growth?
This tool adds each month’s investment at the end of the month (an ordinary annuity). Investing at the start of each month instead would add a little more, since every dollar gets one extra month to compound.
How does this differ from a lump-sum calculator?
A lump sum grows one amount from day one. This spreads equal investments over time, so less money is compounding in the early years and the final figure is lower than an equal total invested up front.
What return is realistic?
Long-run diversified stock returns have averaged roughly 7% after inflation, with big year-to-year swings. Using a conservative rate keeps the projection honest.
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Educational estimate, not investment or tax advice. Returns are never guaranteed and past performance does not predict the future. Confirm with a licensed advisor.