Downtime cost calculator
Estimate contribution at risk from a production stop, with separate restart, scrap and overtime costs.
Result
Inputs used
- Downtime (min)
- 60
- Recoverable good units per hour
- 120
- Contribution per good unit (currency)
- 8
- Extra scrap / restart / overtime cost
- 150
| Potentially lost good units | 120 units |
|---|---|
| Contribution at risk | 960 currency |
| Extra incident costs | 150 currency |
| Estimated economic exposure | 1110 currency |
Contribution is selling price less avoidable variable costs. If output is recovered later or the stopped asset is not the constraint, contribution at risk is not automatically lost revenue. Avoid counting restart costs twice.
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Formula and worked example
Potentially lost good units = downtime minutes / 60 × recoverable good-unit rate per hour. Contribution at risk = potentially lost good units × contribution per good unit. Economic exposure adds separately entered incident costs.
A 60-minute stop at 120 good units/hour and contribution of 8 currency units per part puts 960 of contribution at risk. Adding 150 of restart and scrap costs gives 1,110 of economic exposure. Enter your own currency consistently; no exchange rate is assumed.
Avoid an inflated business case
Use contribution after avoidable variable costs, not sales price. If another operation is the constraint or lost output can be recovered without displacing sales, the contribution may not actually be lost. Model the recoverable amount and document the assumption.
Do not add normal fixed labor or depreciation again if they do not change because of the stop. Extra overtime, expedited shipping or restart scrap may be relevant, but keep overlapping costs out of the same estimate. Pair the calculation with the downtime worksheet to preserve its evidence.
Frequently asked questions
Is the result lost revenue?
It is an estimate of contribution at risk plus incremental incident costs. Actual loss depends on the bottleneck, demand, inventory and recovery options.
Can I compare stops by cost?
Yes, if rate and contribution assumptions are comparable. Keep duration, frequency and safety consequences visible alongside the cost ranking.
Go deeper
Cite this page: Downtime cost calculator
, Shopfloor. https://shopfloor.space/tools/downtime-cost-calculator/