How to Calculate ROI: A Practical Guide for Any Investment

Return on investment (ROI) is the universal yardstick for measuring whether an investment — financial or otherwise — was worth the money. Whether you are evaluating a stock, a rental property, a marketing campaign, or a business expansion, ROI tells you how efficiently your capital was deployed.

The Basic ROI Formula

ROI = [(Final Value − Initial Cost) / Initial Cost] × 100

This gives you a percentage that represents your gain (or loss) relative to your investment. A positive ROI means you made money; a negative ROI means you lost money.

Worked Examples

Stock Investment

You buy 100 shares at $50 each ($5,000 total). A year later, you sell at $62 per share ($6,200) and received $150 in dividends.

ROI = [($6,200 + $150 − $5,000) / $5,000] × 100 = 27%

Rental Property

You buy a rental property for $200,000 and spend $20,000 on renovations. After one year, you have collected $24,000 in rent and paid $10,000 in expenses (taxes, insurance, maintenance). The property is now worth $215,000.

Total gain = ($215,000 − $220,000) + ($24,000 − $10,000) = $9,000

ROI = ($9,000 / $220,000) × 100 = 4.1%

Business Marketing Campaign

You spend $3,000 on a Google Ads campaign that generates $12,000 in new revenue with a 40% profit margin ($4,800 profit).

ROI = [($4,800 − $3,000) / $3,000] × 100 = 60%

Common ROI Mistakes

• Ignoring the time factor: A 20% ROI over one year is very different from 20% over five years. To compare investments with different holding periods, use annualized ROI.
• Forgetting all costs: Include transaction fees, taxes, maintenance, and opportunity cost in your calculation.
• Comparing unlike investments: ROI does not account for risk. A 10% return from a savings account is not the same as 10% from a speculative stock.
• Using projected rather than actual figures: Estimates are useful for planning, but track your real ROI after the fact to improve future decisions.

Annualized ROI

To compare investments held for different periods, use the annualized formula:

Annualized ROI = [(1 + ROI)^(1/n) − 1] × 100

Where n is the number of years. A total ROI of 50% over 3 years = an annualized ROI of about 14.5%.

Calculate Your ROI

Use our investment calculator to model different scenarios and see how various rates of return compound over time. Knowing your ROI helps you allocate capital to the investments that generate the most value.

ROI is a simple but powerful tool. Use it consistently, account for all costs and time, and you will make smarter financial decisions across every area of your life.