Downtime Cost Calculator

Downtime cost = downtime hours × [(lost units per hour × contribution margin per unit) + (idle staff × hourly labour rate)]. It’s what the stop cost you: the margin on units you didn’t make, plus wages paid for no output.

Use contribution margin — selling price minus variable cost — not selling price. When the line stops you lose the sale, but you also don’t spend the materials and energy for those units.

Treat the result as the floor, not the ceiling: scrap from the stop and restart, overtime to catch up and late-delivery penalties come on top. The per-hour figure is the one to use when weighing a spare part or a PM task against the breakdown it prevents.

This calculator is for one line over one incident or period, entered by hand in your own currency. MachDatum CMMS tracks downtime hours per asset from breakdown work orders, so the first input is already on record.