What one unplanned stop actually costs, per hour and per year
| Source | Finding | Figure |
|---|---|---|
| ITIC 2024 Hourly Cost of Downtime survey | Share of mid-size and large enterprises losing more than $300,000 per hour | >90% |
| ITIC 2024 | Enterprises reporting $1M–$5M per hour | 41% |
| Siemens/Senseye, True Cost of Downtime 2024 | Unplanned downtime cost, automotive plants (highest sector) | ~$2.3M/hour |
| Siemens/Senseye 2024 | Downtime losses across Fortune Global 500 industrial firms | ~11% of revenue (~$1.4T total) |
These are headline survey figures for context, not benchmarks to budget from. The ITIC numbers skew toward IT and services firms; heavy-industry rates depend on your own margin, staffing, and contractual penalties, which is what the calculator above estimates.
| Cost bucket | How to estimate it | Include in rate? |
|---|---|---|
| Lost production margin | Units per hour × contribution margin per unit | Yes, core |
| Idle direct labor | Workers on the stopped line × loaded hourly cost | Yes, core |
| Restart scrap & rejects | Average scrap value per restart for that asset | Yes, as one-off |
| Maintenance labor & parts | Technician hours × rate + consumed spares | Yes, as one-off |
| Expedited freight / overtime | Typical catch-up premium per event | Yes, as one-off |
| Contract penalties / SLA credits | Per-contract exposure at risk during a stop | Case by case |
| Fixed overhead (rent, depreciation) | You pay it whether the line runs or not | No, not incremental |
Every maintenance budget fight eventually comes down to one number: what does an hour of stopped production actually cost? This calculator builds it from the pieces you already know, instead of borrowing an industry headline that was measured on someone else's plant.
Event cost = hours × (units per hour × margin per unit + idled workers × loaded hourly cost) + one-off restart costs. The recurring pieces form the hourly rate; the restart, scrap, and expedite costs land once per event. Annualized cost = events per year × event cost.
Pull the last few downtime events from your CMMS or the maintenance log. Units per hour is the line's demonstrated rate; margin per unit is contribution margin (price minus variable cost), not price. Loaded hourly cost means wages plus benefits and payroll taxes, often 1.3 to 1.5 times base wage. If restart scrap varies wildly, use a six-month average.
A bottling line stops for 3 hours on a failed drive. The line makes 1,200 units an hour at a $2.10 contribution margin, so lost margin runs $2,520 an hour. Fourteen staff are idled at a $28 loaded rate, adding $392 an hour: the blended cost is $2,912 an hour, about $48.53 a minute. The restart scrapes $1,800 of product. Total: 3 × $2,912 + $1,800 = $10,536 for one event.
Annualization is where budgets change. At 25 such events a year, that line is bleeding $263,400 annually, and a monitoring or spare-drive strategy that prevented even a third of them is worth $87,800 a year. For scale, published surveys put enterprise downtime at six figures per hour: ITIC's 2024 survey found over 90% of large firms lose more than $300,000 an hour, and Siemens' analysis puts automotive plants at roughly $2.3 million. Your plant's number will usually sit well below those headlines, but it is almost always larger than the maintenance budget line it competes against.
There is no one average, and the published ranges are enormous. ITIC's 2024 survey found that over 90% of mid-size and large enterprises lose more than $300,000 per hour of downtime, and Siemens' 2024 analysis put automotive manufacturing at the extreme end, about $2.3 million per hour. Your number depends on your own margin and staffing, which is why measuring it beats borrowing an industry figure.
Contribution margin, usually. When a line stops you still pay rent, depreciation, and salaried staff, but you lose the margin on unsold units, so revenue overstates the loss. The exception is make-up production: if lost volume can't be recovered on another shift, or contracts carry penalties and service credits, the true loss climbs toward revenue. Start with margin per unit, then add penalty exposure separately if you have it.
Beyond lost margin and idle direct labor: restart scrap and reject/rework after the line comes back, expedited freight to catch up, overtime, equipment damage from the failure itself, technician call-outs, contractual service credits, and the quality dip that follows many restarts. Safety incidents during rushes to restart are the costliest category of all, though they belong in a risk register more than a rate card.
Annualize your downtime cost (events per year × average event cost), then apply a realistic reduction, typically 30-50% for condition monitoring programs. If $263,400 a year becomes $158,000, the tooling and sensors that capture $105,000 annually pay for themselves on a short horizon. That cost-of-the-problem framing is exactly what makes maintenance budgets competitive with production projects.
Usually not in the same bucket. Planned stops, changeovers, and scheduled maintenance are real costs but they're controlled and schedulable, which is why OEE tracks them separately as availability losses. The dollars in an unplanned-downtime case are the volatile ones: they arrive without warning, carry restart penalties, and consume maintenance labor at overtime rates.