How to Calculate Downtime Cost
A defensible downtime estimate separates physical lost output, contribution margin, recovery expense, contractual consequences, and what can actually be recovered.
Begin with the event boundary
Record start, end, rate loss, product affected, and whether upstream or downstream inventory buffered the event. Not every hour of equipment downtime is a lost-sale hour.
Value lost contribution carefully
Use contribution margin rather than revenue when an outage causes truly unrecoverable output. Then add traceable labor, expedited freight, materials, environmental, penalty, and quality costs. Avoid counting the same revenue loss as both lost margin and a penalty proxy.
Use scenarios, not false precision
For major decisions, show a conservative, expected, and severe scenario. Make recovery assumptions visible: overtime capacity, inventory drawdown, customer demand, and rescheduling can change the result substantially.
Turn cost into priorities
Use event consequence with frequency, exposure, and safety risk to prioritize reliability work. A low-frequency bottleneck event can merit more attention than a common but low-impact nuisance trip.
Related tools
Use the downtime cost calculator, lost production calculator, and maintenance ROI calculator.