Up to $2.3M / hour
Automotive
An idle production line at a major automotive plant. The same report puts the rise from 2019 to 2023 at 113% — against 19% US inflation over the period.
Planning Benchmarks
The cost of unplanned downtime, by sector
Quotable figures from named public sources — and an honest framing of which number you should actually plan with.
Planning ranges, not your number: every figure below is a published benchmark for the largest operations in its sector. Use them to frame the value of avoided downtime — then calculate your own exposure from your line's output and margin.
$59M / hour
Heavy industry (largest plants)
The headline upper-bound figure for the largest heavy-industry operations — 1.6× the 2019 level. A useful ceiling, not a number to apply to a mid-size line.
$1.4 trillion / year
Fortune Global 500, combined
Estimated annual loss to unplanned downtime across the world's 500 largest firms — about 11% of their total revenue.
≈ 27 hours / month
Average large plant
Unplanned downtime at a typical large plant, down from 39 hours/month in 2019 — roughly 324 hours a year still lost.
Source: Siemens, The True Cost of Downtime 2024 (survey of 181 professionals across automotive, FMCG, heavy industry, and oil & gas). Figures are sector headline benchmarks, reproduced here as planning references.
How to plan with these
The only number that matters is your line's margin per hour
Benchmark headlines are good for one thing: showing leadership that avoided downtime is worth a serious conversation. They are useless as a direct input to your business case, because they describe plants far larger than most lines. The defensible planning number is built from three values you already have — the output value of the line per hour, the unplanned-downtime hours you actually lose, and a realistic reduction target from a bounded monitoring pilot.
That is exactly what the downtime cost calculator does. Start from your own figures, keep the reduction target conservative, and you have a number you can defend in a budget meeting — not a borrowed headline.
Open the downtime cost calculator Frequently asked
Questions leaders ask about downtime cost
What is the average cost of unplanned downtime per hour?
There is no single average that fits every plant — it depends on the line's output value and margin. The published headline figures from the Siemens True Cost of Downtime 2024 report range from up to $2.3 million per hour in automotive to a $59 million per hour upper bound for the largest heavy-industry operations. For planning your own case, the number that matters is your line's contribution margin per hour, not an industry headline.
How much downtime does a typical plant have?
The same report puts a typical large plant at about 27 hours of unplanned downtime per month — roughly 324 hours a year — down from 39 hours a month in 2019. Improvement is real, but the cost per hour has risen faster than the hours have fallen, so total exposure has grown in several sectors.
Why are these figures so much higher than my plant's?
Headline benchmark figures describe the largest operations — full automotive plants or major heavy-industry sites. They are useful as a directional ceiling and to frame the value of avoided downtime, but they should never be transplanted onto a smaller line. Calculate your own exposure from your hourly output value, your unplanned-downtime hours, and a realistic reduction target.