Investment Calculator

Calculate future value of investments with regular contributions and compound growth.

How Investment Returns Work

The stock market has historically returned about 7–10% annually (adjusted for inflation, ~7%). This calculator uses compound interest to show how your money grows over time.

The Power of Starting Early

Investing $200/month for 30 years at 7% grows to $243,994. Waiting 10 years and investing for just 20 years yields only $104,430 — less than half, despite investing for a shorter time.

Common Investments by Return Rate

How Investment Growth Works

An investment grows from two engines: the money you contribute and the returns those contributions earn over time. When returns are reinvested they start earning their own returns — compounding — which is why starting early often matters more than starting big. This calculator projects the future value of a starting amount plus regular contributions at an assumed annual rate of return.

A Worked Example

Suppose you start with $5,000, add $200 a month, and earn 7% a year. Over 20 years you'd contribute $53,000 of your own money, but the balance would grow to roughly $123,000 — more than double — thanks to compounding. Stretch the horizon to 30 years and the gap widens sharply. See the same effect on a lump sum with the compound interest calculator.

Reading the Result Honestly

Projections assume a steady return, but real markets rise and fall. Use a conservative rate (broad stock markets have historically averaged around 7% after inflation, though future returns are not guaranteed), and remember the figure is before taxes and fees. This tool is for planning and education, not a promise of returns.

Frequently Asked Questions

The S&P 500 has historically averaged 7-10% annually. After inflation, the real return is about 7%. Use 6-7% for conservative projections.
More frequent compounding (daily vs. annual) produces slightly higher returns. The difference is small but grows meaningful over decades.
Both work well. Monthly contributions reduce timing risk via dollar-cost averaging. A lump sum works well if invested during market downturns.