ROI Calculator
Interpreting return on investment
ROI compares net gain or loss with the starting investment. It is useful for a quick comparison, but it does not account for how long an investment was held, cash flows during the period, taxes, fees, or risk.
Formula and method
ROI = (final value − initial investment) ÷ initial investment × 100%.
Worked example
An investment rising from $10,000 to $15,000 has a $5,000 gain and a 50% ROI.
How to interpret the result
ROI answers how large the gain or loss is relative to the starting investment. It does not say how quickly that return occurred. A 20% ROI over one year and over ten years have very different implications, so compare equal holding periods or calculate an annualized return when time matters.
Important limitations
- Compare investments over the same time period.
- Use annualized return when holding periods differ.
Common questions
Should fees and taxes be included?
For a decision-quality comparison, use a final value after relevant transaction costs, ongoing fees, and taxes. Excluding them makes the reported ROI a gross return rather than the return retained by the investor.
Can ROI be below negative 100%?
A conventional unleveraged investment cannot lose more than the amount invested, but leverage, liabilities, or additional cash calls can create losses greater than the original outlay.
Related tools
Method and examples reviewed September 8, 2026.