Downtime Cost Calculator
What an Idle Line Actually Costs
Unplanned downtime is easy to notice and easy to underestimate — the visible cost is the idle labor, but the larger figure is usually the production that never happened. This calculator offers two levels of detail: a quick hours-times-rate estimate, or a fuller breakdown that separates lost production value from labor cost incurred during the stoppage.
The Formulas
Detailed:
Lost Units = Downtime Hours × Units per Hour
Total Cost = (Lost Units × Cost per Unit) + (Downtime Hours × Labor Cost per Hour)
Worked Examples
| Mode | Inputs | Calculation | Total cost |
|---|---|---|---|
| Simple | Hourly cost $1,200 | 3 × $1,200 | $3,600.00 |
| Detailed | 50 units/hr, $25/unit, $180/hr labor | (150 × $25) + (3 × $180) | $4,290.00 |
The detailed mode's total ($4,290) is higher than the simple estimate ($3,600) for the same 3-hour stoppage, because it captures lost production value on top of labor cost — a gap that's easy to miss with a rough hours-times-rate figure alone.
Where This Matters
- Justifying maintenance investment — a clear downtime cost figure makes it easier to justify spending on preventive maintenance or spare parts inventory.
- Prioritizing which line to fix first — comparing downtime cost per hour across multiple lines identifies where an outage hurts the most.
- Post-incident reporting — a documented cost figure is standard input for root-cause-analysis and continuous improvement reviews.
How to Use This Calculator
- Choose the mode: Simple (Hours × Rate) or Detailed (Lost Units + Labor).
- For Simple: enter Downtime Hours and Hourly Cost Rate.
- For Detailed: enter Downtime Hours, Units per Hour, Cost per Unit, and optionally Labor Cost per Hour.
- Select Calculate to see the total downtime cost.
Related Calculations
See how downtime affects overall equipment effectiveness with the OEE Calculator, or check current machine utilization with the Machine Utilization Calculator.