Finance Calculators
ROI Calculator
Return on investment sets the net gain against what was paid for it: subtract the cost from the final value, divide by the cost, and multiply by one hundred. This ROI calculator also reports the net gain in money and, when a period is entered, the annualised return that puts investments of different lengths on one footing.
Calculator
How It Works
ROI = (final value − cost) ÷ cost × 100. A cost of 10,000 that came back as 12,100 is a net gain of 2,100; divided by 10,000 and multiplied by 100 that is an ROI of 21 %. The annualised ROI compounds the same result over the period: (final value ÷ cost) ^ (1 ÷ years) − 1, times 100, so 21 % over two years is 10 % a year. ROI says nothing about risk, and it is only comparable across investments with the same period and the same definition of cost.
About This Calculator
What It Does
Calculate the return on an investment from the cost and the final value: the net gain in money, the ROI as a percentage, and the annualised ROI when a period is supplied.
Worked Example
10,000 invested and 12,100 returned: the net gain is 2,100 and the ROI is 21 %. Over a two-year period the annualised ROI is 10 % a year.
Real-World Usage
Check whether an investment paid off, compare two options of different lengths, or judge a marketing or project budget by what it returned.
Local Context
The abbreviation ROI stands for return on investment and is used as-is in every country; the arithmetic is currency-independent and ignores taxes, fees and risk.
Last reviewed: October 2026.
Frequently Asked Questions
What is return on investment?
It sets the net gain against what was paid for it: net gain divided by cost, times 100. A net gain of 2,100 on a cost of 10,000 is an ROI of 21 %.
Why is a period needed for the annualised figure?
The simple ROI has no time in it: 21 % over two years and 21 % over one year look the same but are not comparable. The annualised ROI puts both on a yearly footing, so 21 % over two years is 10 % a year.
Can ROI be negative?
Yes. When the final value is below the cost the net gain is negative and so is the ROI — for example −20 % on a cost of 1,000 that returned 800. A final value of zero is a total loss of −100 %.