Finance

ROI Explained: More Than Just a Percentage

Morecalcs Team 2026-07-08· 6 min
How to compute return on investment — and why annualizing it changes the story.

The formula

ROI = (Gain − Cost) / Cost × 100. A $10,000 investment worth $12,500 has a 25% ROI.

Why annualized ROI matters

That 25% over 5 years is only about 4.56% per year. Over 6 months it's about 56%. Time changes the meaning of the same headline.

Costs you forget

Fees, taxes, opportunity cost, and time invested. A "50% ROI" flip that took a year of weekends may underpay minimum wage.

Compare apples to apples

Always report ROI as CAGR (compound annual growth rate) when comparing multi-year investments.

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