What this calculator does
ROI is a simple way to compare the gain from an investment with the cost of making it. It is useful for campaigns, equipment purchases, projects and investment examples.
Formula used
ROI equals gain divided by cost, multiplied by 100. Gain is the final value or return minus the original cost. Annualised ROI spreads the return across the chosen time period.
How to read the result
ROI is easy to read, but it can hide timing, risk, cash flow and opportunity cost. Use it as a first comparison, not the whole decision.
Assumptions
- Uses simple ROI before tax and fees.
- Annualised ROI assumes compounding across the time period.
- Does not adjust for risk, inflation or uneven cash flows.
Sources and checks
This calculator uses a standard public formula. Where rules or thresholds can change, source links are listed on the relevant page.
Frequently asked questions
What is a good ROI?
It depends on risk, time and alternatives. A high ROI over a long period may be less attractive than a lower return achieved quickly with less risk.