ROI ACADEMY
Every metric the calculators produce, explained with definition, formula, a real example and the rule that keeps it honest.
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9 articles
Contribution margin, variable and fixed costs
The one split that determines whether an extra order helps or hurts.
7 min18/06/2026
Direct vs indirect labour
Only one of them belongs in your cost per garment.
5 min12/06/2026
Facility costs explained — allocation is not saving
Rent, floor space and overhead must be allocated, but they rarely change with a machine.
9 min05/07/2026
Payback vs ROI: two questions, two answers
Payback measures risk exposure in time. ROI measures profitability in money.
5 min08/07/2026
What is IRR?
The internal rate of return is the discount rate at which the investment breaks even.
6 min30/06/2026
What is NPV?
Net present value prices the fact that money next year is worth less than money today.
7 min30/06/2026
What is ROI — and what it is not
Return on investment compares net gain to capital employed over a defined horizon.
6 min08/07/2026
Why free capacity is not revenue
Capacity becomes money at the moment an invoice exists — and only at contribution margin.
7 min11/07/2026
Why released labour hours are not cash savings
Time freed on the shop floor changes the payroll only under specific conditions.
8 min11/07/2026