Formula & Calculator
Return on Investment (ROI)
Measures the profitability of an investment as a percentage of the amount originally invested.
Interpretation
ROI (%) = ((Gain − Cost) / Cost) × 100. Measures profitability of an investment relative to its cost. Used to compare investment efficiency.
Variables
| Symbol | Quantity | Unit |
|---|---|---|
| ROI | Return on investment | % |
| Gain | Final value or return from investment | currency |
| Cost | Original amount invested | currency |
What it means
Return on Investment (ROI) is a simple performance measure that evaluates the efficiency of an investment. It is calculated by dividing the net profit (gain minus cost) by the cost of the investment, expressed as a percentage. ROI is widely used in business and personal finance to compare the profitability of different investments, marketing campaigns, and capital projects. It does not account for the time value of money, so it is best used for short‑term investments or as a first‑pass metric. Understanding ROI is essential for decision‑making and for justifying resource allocation.
Worked example
Return on Investment – Two Detailed Examples
Real‑World| Parameter | Value |
|---|---|
| Cost | 1000 |
| Gain | 1200 |
| Parameter | Value |
|---|---|
| Cost | 5000 |
| Gain | 4500 |
Common mistakes
- Gain: The final value of the investment minus the initial cost – can be negative (loss).
- Cost: The total amount invested (initial outlay).
- ROI: A percentage – multiply by 100.
- Time: ROI does not account for the time period – for comparisons, use annualised ROI.
- Cash flows: Include all costs and returns – not just the final value.
Applications
Return on Investment (ROI) measures the efficiency of an investment by comparing the gain (or loss) to its cost. Expressed as a percentage, ROI is one of the most widely used performance metrics in business and finance. It helps managers evaluate past investments, to prioritise future projects, and to communicate results to stakeholders. ROI is used for marketing campaigns, equipment purchases, R&D projects, and real estate. By applying ROI, organisations can allocate capital to the highest‑yielding opportunities and justify expenditures. However, ROI does not account for time or risk, so it is often supplemented with other measures. Nevertheless, its simplicity and universality make it indispensable for decision‑making.
- Project performance evaluation and post‑audit reviews
- Capital allocation and budget prioritisation
- Marketing campaign effectiveness measurement
- Real estate investment profitability analysis
- Education – teaching basic financial analysis
Frequently Asked Questions
ROI (%) = ((Gain − Cost) / Cost) × 100. It measures the profitability of an investment relative to its cost, expressed as a percentage. A positive ROI means the investment generated a gain.
An ROI of 25% means that for every dollar invested, you earned $0.25 in profit (net gain) after recovering the initial cost. It is a measure of efficiency.
ROI is a general measure of return on a specific investment. ROE (Return on Equity) is specifically the return on shareholders’ equity, calculated as net income / shareholders’ equity. ROE is a company‑wide performance metric.
ROI is a total return, not annualized. For comparing investments held for different periods, you need to annualize ROI: Annualized ROI = ((1 + ROI)^(1/t) − 1), where t is years.
- It does not account for the time value of money.
- It ignores the risk of the investment.
- It can be manipulated by adjusting the cost or gain figures.
- It may not be comparable across investments with different durations.
Marketing ROI (ROMI) measures the return on marketing spend: (incremental revenue attributable to marketing − marketing spend) / marketing spend × 100. It evaluates the effectiveness of campaigns.
It depends on the industry and risk. For a low‑risk investment (like bonds), a 5‑10% ROI may be acceptable. For high‑risk ventures (like startups), investors may expect 30% or more.
For rental property: ROI = (Annual Rental Income − Operating Expenses − Mortgage Interest) / Total Cash Invested × 100. This gives the cash‑on‑cash return, which is a common ROI measure.
ROI is a percentage return on the cost; NPV is a dollar‑value measure of value creation. NPV accounts for the time value of money and all cash flows, while ROI does not.
Yes, if the gain is less than the cost (i.e., a loss). A negative ROI indicates the investment lost money.