ROI Calculator
Calculate return on investment as a percentage.
This tool runs entirely in your browser. Your files are never uploaded to a server.
200.00
Net gain
20.00%
ROI
What this tool does
Calculates a simple return on investment (ROI): the net gain from an investment expressed as a percentage of the amount originally invested.
How to use it
Enter the amount invested and the amount returned, and the net gain and ROI percentage update instantly. Reset returns to the default example of 1,000 invested and 1,200 returned.
Worked example
Investing 1,000 and getting back 1,200 gives a net gain of 200 and an ROI of (200 / 1,000) × 100 = 20%. Getting back only 800 instead would give a net gain of −200 and an ROI of −20%, showing a loss rather than a gain.
Formula
ROI = (amount returned − amount invested) / amount invested × 100. The tool requires the amount invested to be a positive number, since dividing by zero or a negative investment wouldn't produce a meaningful percentage.
Interpreting the result
A positive ROI means the investment returned more than it cost; a negative ROI means it returned less, regardless of how large the numbers are. Because it's a ratio, a 20% ROI on 100 and a 20% ROI on 1,000,000 represent the same relative outcome even though the dollar gains are very different.
Limitations
This is a simple, point-in-time ROI: it doesn't annualize returns, so a 20% gain over one month and a 20% gain over five years show the same 20% figure here even though they're very different outcomes. It also doesn't account for fees, taxes, inflation, or additional contributions or withdrawals during the holding period. To compare returns over different time horizons, use the Compound Interest Calculator instead.
Privacy and processing
All calculations run locally in your browser using JavaScript. The amounts you enter are never uploaded or stored.
Frequently Asked Questions
- How is ROI calculated?
- ROI = (amount returned − amount invested) / amount invested × 100.
- Can ROI be negative?
- Yes, if the amount returned is less than the amount invested, ROI is negative, indicating a loss.
- Does this account for the time period of the investment?
- No, this is a simple ROI calculation; it doesn't annualize returns over different holding periods. A 20% ROI over one month and a 20% ROI over five years both show 20% here.
- What happens if I enter zero or a negative investment amount?
- The result is blank, since dividing by zero or a negative amount can't produce a meaningful ROI percentage. Enter a positive amount invested.