ROI Calculator
Calculate return on investment and net gain/loss from an initial investment and either a final value or a gain amount.
How to Use
- Choose whichever numbers you already have — the final value your investment is now worth, or the dollar gain (or loss) you already know — from the options above the form.
- Enter your initial investment amount and the other figure.
- The result shows your net gain or loss and ROI as a percentage — a negative number means a loss, which this calculator fully supports.
Formula
- From final value
- gain = final_value − initial_investment, ROI% = gain ÷ initial_investment × 100
- From gain
- ROI% = gain ÷ initial_investment × 100
Worked Example
A $1,000 investment now worth $1,500.
- Net gain: $1,500 − $1,000 = $500
- ROI: $500 ÷ $1,000 × 100 = 50%
Result: Net gain/loss: $500.00 / ROI: 50%
About This Tool
What this tool does
This calculator finds your return on investment (ROI) and net gain or loss, either from an initial investment and its current/final value, or from an initial investment and a known gain (or loss) amount directly.
When to use it
Use it to check the return an investment, purchase, or project actually produced, or to compare the ROI of two different outcomes on a like-for-like percentage basis.
What the result means
Net gain/loss is the plain dollar difference — positive for a gain, negative for a loss. ROI is that same gain or loss expressed as a percentage of what you originally put in, which is what makes returns of different sizes comparable to each other.
Assumptions & limitations
This is a simple, point-in-time ROI: it divides your total gain by your initial investment and does not include how long you held the investment. A 50% ROI over one month and a 50% ROI over ten years are reported identically here, because no holding period is collected — if you want a rate that accounts for time (an annualized return), you need to calculate that separately using your own holding period; this tool does not model it. This tool also assumes you cannot lose more than 100% of your initial investment (no leverage or margin), so a loss is capped at the full amount invested. This is for informational purposes only, not investment or financial advice.