Cost of Downtime Calculator
Unplanned stops cost more than the hour on the clock: the margin you didn't make, the crew you paid to wait, and the overtime to catch up. Put in your numbers.
The math, in plain view.
The calculator adds four costs for each month: lost contribution on output you never recover (hours × units per hour × share not recovered × contribution per unit), idle labor for the crew stopped with the line (hours × people × loaded rate), recovery overtime for the output you do catch up (hours × share recovered × people × loaded rate × (1 + premium)), and other stop costs such as scrap and restart.
It is deliberately simple. The biggest number is usually lost contribution, and it only counts if the line is your constraint. If a non-constraint stops and you catch up on straight time, the real cost is close to the idle labor alone.
What counts as downtime?
Any unplanned stop of the asset or line you are measuring: breakdowns, material shortages, waiting on quality, changeovers that run long. Planned maintenance and planned changeovers are not downtime for this purpose.
Why does the constraint matter?
An hour lost at the bottleneck is an hour lost for the whole plant. An hour lost elsewhere can often be absorbed by buffer, so its cost is mostly labor.
What should I do with the number?
Log every stop for two weeks with a reason code. The top three reasons usually account for most of the hours, and they are where to start.
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More calculators: Inventory carrying cost · OEE · Dollars to hours