What the ROI Calculator does
This tool turns two numbers into a clear measure of how well an investment performed. You enter what you put in and what it became, and it returns the return on investment as a percentage along with the net profit in money. It helps investors comparing stocks or funds, small business owners checking whether a purchase paid off, and marketers measuring the payback on a campaign. Because ROI is a percentage, you can compare a small bet and a large one on equal footing.
How to use it
- In the Initial investment field, enter the amount you originally put in (for example, 1000).
- In the Final value field, enter what the investment is worth now or what you sold it for (for example, 1300).
- Click Calculate.
- Read the result: the ROI (%) appears alongside the net profit, so 1000 growing to 1300 shows a 30% ROI and 300 in profit.
- Change either field and calculate again to compare different scenarios.
A quick tip
A negative result means a loss, not a gain. If the Final value is lower than the Initial investment, both the ROI percentage and the net profit come back negative, which is a fast way to spot an underperforming investment. Keep in mind that basic ROI does not account for how long the money was invested, so a 30% return over one month is very different from 30% over five years. For long holdings, compare the time periods too, and remember to include fees or taxes in your final value if you want the numbers to match your real take-home.
This tool runs entirely in your browser, stays private, is completely free, and needs no sign-up.
Frequently asked questions
- How do I calculate ROI?
- Subtract the initial investment from the final value to get the net profit, then divide that profit by the initial investment and multiply by 100. For example, 1000 growing to 1300 gives a 30% ROI.
- What is the difference between ROI and net profit?
- Net profit is the raw money you gained or lost, while ROI shows that gain as a percentage of what you put in. This tool gives you both so you can compare investments of different sizes fairly.
- Is the ROI calculator free and private?
- Yes, it is free with no sign-up. All math runs locally in your browser, so the amounts you type are never sent to a server.
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Last updated: June 17, 2026