Investment Calculator

Project the future value of an investment with a starting amount, monthly contributions and an expected yearly return.

How to use the Investment Calculator

  1. Enter your starting amount and monthly contribution.
  2. Enter the expected yearly return and the number of years.
  3. Read the projected value and open the table to see growth year by year.

How investment growth is calculated

Each month the balance earns one twelfth of the yearly return and the monthly contribution is added. Over time, growth is earned on earlier growth, which is compounding.

FV = P(1 + i)n + C × ((1 + i)n − 1) ÷ i

P is the starting amount, C is the monthly contribution, i is the monthly return and n is the number of months.

Choosing a return rate

Long-run stock market returns have averaged roughly 7–10% a year before inflation, but individual years vary widely and losses happen. Use a cautious figure and try several rates to see a range of outcomes. To see results in today’s money, subtract expected inflation from the return.

Results are estimates for planning. They are not financial advice and do not include every fee a lender or provider may charge.

Frequently asked questions

What return rate should I use?

A cautious long-term figure for a diversified stock portfolio is 5–7% a year after inflation. Bonds and savings accounts are lower.

How does compounding help?

Returns are earned on previous returns as well as on your contributions, so growth speeds up the longer the money stays invested.

Are the results guaranteed?

No. The calculator assumes a constant return every year. Real investments rise and fall and can lose value.

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