Why an online ROI calculator beats a spreadsheet
Spreadsheets are flexible but slow: every new scenario means copying tabs, fixing formulas and second-guessing references. An online calculator collapses the same decision into two inputs and three numbers, and stays consistent across every device you open it on.
What you'll see
- Net gain — the pound figure you'd keep over the chosen horizon
- Payback — months until the investment pays for itself
- Total ROI — the standard percentage figure
- Annualised ROI — so 12-, 24- and 36-month decisions are comparable
Beyond the quick calculator
If the decision is bigger than a gut check — a new hire, a marketing campaign, or a five-figure capital purchase — open the full industry modeler. It factors in running costs, depreciation, UK tax relief and seasonality so the number you take to your accountant actually holds up.