How to use this calculator
- Enter your own values in the labeled fields. Check the units and assumptions before comparing results. Only the fields needed for your selected calculation mode are shown.
- Your answer updates automatically. Review the calculation steps to see exactly how it was calculated.
- Copy, share, save, or download your result. Saved inputs stay on this device.
How the calculation works
Investment projections describe a scenario, not a forecast. Returns fluctuate and the order of gains and losses can matter when you add or withdraw funds. Use several return assumptions rather than relying on a single outcome. The chart separates your contributions from modeled growth so you can see what each contributes.
A worked example
With a 0% annual return, $10,000 plus $200 per month for 10 years becomes exactly $34,000.
Reading your result
Use the main result together with its units and supporting figures. Display values are rounded; calculations keep their underlying precision. A change in inputs or assumptions can change the answer. Compare the step-by-step working with your intended use before relying on an estimate.
Frequently asked questions
Does the model account for market risk?
No. It uses a constant return to make scenarios comparable.
Is this investment advice?
No. This is an educational arithmetic tool, not a recommendation to buy or sell an investment.
Sources & methodology
This calculator uses the mathematical identity and assumptions stated above. No current rates, prices, or external data are loaded. Conversion tools use international unit definitions.
Formula review: October 24, 2026. Read our methodology.