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Investment Calculators

Investment Calculator

Enter a starting balance, what you add each month and a realistic long-run return to see how the balance is expected to develop.

$
$/month
%
years

Projected value

$341,238

Total invested
$140,000
Investment growth
$201,238
Growth multiple
2.44×
Projected balance by year
Yr 1Yr 2Yr 3Yr 4Yr 5Yr 6Yr 7Yr 8Yr 9Yr 10Yr 11Yr 12Yr 13Yr 14Yr 15Yr 16Yr 17Yr 18Yr 19Yr 20

How this calculator works

FV = P(1 + r)^n + C × [((1 + r)^n − 1) ÷ r]

P
the starting amount
C
the regular contribution
r
the periodic return
n
the number of periods

Important considerations

  • Returns are assumed to be smooth; real markets are not.
  • Fees, taxes and inflation all reduce the outcome.

Learn more

Terms used here

Frequently asked questions

What return should I assume?

Use a conservative long-run figure and test a lower one. Small changes to the assumption compound into large differences.

Disclaimer

Legamoney calculators are educational tools. Results are estimates based on the figures you enter and do not constitute financial, tax or legal advice.

Last reviewed 2026-08-01