Investment Calculator

Project the future value of an investment with an initial amount and monthly contributions.

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  • 🔒 Files never leave your device
  • ⚡ Converted in your browser
  • ✅ No account required

Investment Calculator: The Complete Guide

Project how your investments could grow. Enter a starting amount, a monthly contribution, an expected annual return, and a time horizon to estimate your future portfolio value and the total returns earned.

Who the Investment Calculator is for

Long-term investors and savers modelling how regular contributions and compounding returns build wealth over time.

How to use the Investment Calculator

  1. Type your values into the fields above — pick your currency or units where the calculator offers them.
  2. Results update automatically as you type; there's no submit button and nothing is sent to a server.
  3. Adjust any input to compare scenarios, then copy the result with a single click.

How it works

The initial amount grows at the expected annual return, while monthly contributions are grown as an annuity. Future value combines both; total returns equal the future value minus everything you contributed.

Features

  • Initial + monthly contributions
  • Projected future value
  • Total invested vs. returns
  • Any currency

How investments compound

Investing combines two engines of growth: your ongoing contributions and the compounding returns on everything already invested. Over decades, returns typically outgrow contributions — which is why starting early matters so much. This is a projection at a constant rate; real markets vary year to year.

Frequently Asked Questions

What return should I assume?

Use a realistic long-run figure for your assets — many investors model broad stock markets around 6–8% before inflation. Lower it for caution.

Are returns guaranteed?

No. This is a projection assuming a steady rate. Actual investment returns fluctuate and can be negative in any given year.

Is this calculator free and private?

Yes. It's completely free with no signup, and every calculation runs locally in your browser, so your numbers never leave your device.