What Is ROI?

Return on investment (ROI) is a performance metric that measures the gain or loss generated by an investment relative to its cost. Expressed as a percentage, ROI answers a simple question: for every dollar invested, how much did you gain or lose? The metric appears across finance, real estate, marketing, and corporate planning because it provides a comparable way to evaluate different types of investments.

The Core Idea

Investments require capital. Whether you buy stocks, fund a marketing campaign, or purchase real estate, you commit money with the expectation of a return. ROI quantifies that return in a single number. A 25% ROI means that for every $100 invested, you gained $25 (or the equivalent in increased value). A negative ROI indicates a loss.

The formula is straightforward: divide the net gain (or loss) by the initial investment, then multiply by 100. Net gain is final value minus initial investment. See the full derivation in our ROI Formula guide.

Why ROI Matters

ROI enables comparison across disparate investments. Without a common metric, it is difficult to judge whether a stock purchase, a rental property, or a business project performed better. ROI normalizes returns by scaling them to the amount invested. A $1,000 gain on a $10,000 investment and a $10,000 gain on a $100,000 investment both represent 10% ROI, making them directly comparable on a percentage basis.

In business, ROI informs capital allocation. Executives use it to prioritize projects, evaluate marketing spend, and assess acquisitions. In personal finance, it helps investors compare asset classes and holding periods. In real estate, it underpins cap rate analysis and property comparisons. For a deeper look at related metrics, see our cap rate and annualized return entries.

Where ROI Is Used

Equity investing: Investors calculate ROI when selling shares. Total return includes both price appreciation and dividends. For multi-year holds, annualized ROI is often more meaningful than simple ROI.

Real estate: ROI appears in rental analysis (rental income versus purchase price and costs) and fix-and-flip projects (sale proceeds versus acquisition and renovation costs). Cap rates, a close cousin of ROI, express net operating income as a percentage of property value.

Business projects: Companies use ROI to evaluate capital expenditures, new product launches, and process improvements. Hurdle rates—minimum acceptable ROI—vary by industry and risk.

Marketing: Marketing ROI measures revenue or profit generated per dollar spent on campaigns. Definitional choices (e.g., which costs to include) affect the result, so consistency matters when comparing campaigns.

Limitations of ROI

ROI is useful but has limitations. It does not account for the time value of money. A 50% return over one year is not equivalent to 50% over ten years. For multi-year investments, annualized ROI addresses this by converting the total return into an equivalent annual rate.

ROI also ignores risk. Two investments with the same ROI can have very different risk profiles. A 20% return on a Treasury bond is not comparable to 20% on a speculative startup. Risk-adjusted metrics such as Sharpe ratio go further, but ROI remains a starting point for quick comparison.

When investments involve multiple cash flows—deposits, withdrawals, dividends—simple ROI becomes inadequate. IRR (Internal Rate of Return) is better suited for those cases. For more on when ROI can mislead, see ROI Limitations.

Summary

ROI is a standard, percentage-based measure of investment performance. It is easy to compute and widely understood. Use it to compare investments and allocate capital, but supplement it with annualized returns for multi-year holds, IRR for complex cash flows, and risk-adjusted metrics when appropriate. Our ROI Calculator can help you compute ROI and annualized ROI for your own scenarios.