ROI Calculator guide
ROI Calculator: Return on Investment
Use our ROI calculator to work out the return on an investment as a percentage, and the annualised return over several years.
By the AllCalculator editorial teamUpdated 16 October 20261 min read
Return on investment (ROI) is the simplest way to measure how well an investment has done. Our ROI Calculator works it out.
How to use the calculator (ROI Calculator)
- Enter the amount invested.
- Enter the amount returned, including the final value and any income.
- Optionally, enter the number of years.
The formulas
- ROI = (return − cost) ÷ cost × 100
- Annualised ROI = (return ÷ cost)^(1 ÷ years) − 1
A worked example
With the calculator's default settings, investing £10,000 and getting back £13,500 is an ROI of 35%. Over 3 years, that's 10.52% a year.
Frequently asked questions
Why annualise ROI?
To compare investments held for different lengths of time. 35% over 3 years is very different from 35% over 10.
What does ROI leave out?
Risk, and the timing of cash flows in between. For uneven cash flows, use our IRR Calculator.
Sources and further reading
Links open official and independent websites in a new tab.
This guide is general information to help you understand your options. It isn't financial, tax, legal or building advice and doesn't take your personal circumstances into account. Figures were checked when the guide was last updated and can change, so confirm anything important with GOV.UK, HMRC, a regulated adviser or a qualified tradesperson.