How ROI Works
Return on investment measures how much profit an investment generated relative to its cost. It is one of the most widely used metrics in finance because it works across almost any asset class or business decision.
The standard formula compares net gain to the amount originally committed. A positive ROI means the investment made money. A negative ROI means it produced a loss. The bigger the ROI, the more efficiently capital was deployed.
The Formulas
ROI = (Net Profit ÷ Initial Investment) × 100
Net Profit = Final Value − Initial Investment − Additional Costs
Annualized ROI = ((Final Value − Costs) ÷ Initial Investment)^(1 ÷ Years) − 1
Annualized ROI converts total return into an equivalent yearly rate using compound growth logic.
Why Costs Change the Result
Gross ROI ignores fees, taxes, and expenses. If you bought a property for €200,000 and sold it for €240,000 but paid €15,000 in renovation and transaction costs, the net profit is €25,000, not €40,000. Including costs produces a real-world result rather than a headline figure.
When to Use Annualized ROI
Basic ROI does not account for how long the investment took. A 30% ROI over 10 years is far less impressive than a 30% ROI over 1 year. Annualized ROI normalizes for time, making it the right metric when comparing investments with different holding periods.
Frequently Asked Questions
What is a good ROI?+
There is no universal threshold. What counts as good depends on risk, time horizon, liquidity, and available alternatives. A 10% annual ROI on a low-risk savings product is very different from 10% on a leveraged property deal. Compare ROI to a relevant benchmark for the asset class.
What is the difference between ROI and annualized ROI?+
Basic ROI measures total return across the full holding period regardless of how long it took. Annualized ROI converts that total return into an equivalent yearly rate using compound growth logic, which makes it easier to compare investments held for different durations.
Can ROI be negative?+
Yes. If the final value minus all costs is less than the original investment, ROI is negative. This means the investment produced a loss. Negative ROI is common when costs are high relative to the return or when the asset lost value.
Should I include tax in the costs field?+
For real-world decision-making, yes. After-tax ROI is a more accurate measure of what you actually keep. Pre-tax ROI is useful for quick comparisons but can overstate profitability if tax rates on gains are significant.
How is ROI different from CAGR?+
ROI measures total gain relative to cost. CAGR (Compound Annual Growth Rate) measures the smoothed annual growth rate of an investment over a period. Annualized ROI and CAGR produce similar results but are calculated differently. Use CAGR when comparing portfolio growth over multi-year periods.