What to include
Use net values consistently.
Include relevant purchase and selling costs and income received. If the ending value already includes reinvested income, do not add the same income again.
Investment performance
ROI Calculator
Calculate total return on investment after purchase costs, selling costs and income received.
Return on investment—
Net gain or loss—
Total initial cost—
Costs and income included
Net ending proceeds—
Break-even ending value—
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Formula
ROI = net gain ÷ total initial cost, where net gain includes ending value and income received, less purchase and selling costs.
Interpretation
ROI measures the whole holding-period result.
A 20% ROI means the net gain equals 20% of the modeled initial cost. It does not say whether that result took one year or ten.
Source
Total cost and investment income matter.
FINRA states that ROI should account for the price paid and investment fees, while stock returns can include dividends and price appreciation.