Machine Utilisation Calculator
How much of a machine's available time is productive — and what an extra hour is worth.
Utilisation is productive time divided by available time.
How the machine utilisation calculator works
Utilisation is productive time divided by available time. It is simple, and its simplicity is the trap: pushing utilisation toward 100% is usually the wrong goal.
Queueing theory is unambiguous about this. As utilisation approaches capacity, waiting time rises non-linearly and then explodes — at 90% utilisation, average queue time is roughly nine times what it is at 50%. A plant running every machine flat out has no ability to absorb variation, so any disruption cascades.
The exception is a genuine bottleneck, where an hour lost is an hour lost for the whole plant. On everything else, high utilisation mostly buys longer lead times.
Formula: utilisation = productive time / available time
Worked examples
| Inputs | Utilisation | Note |
|---|---|---|
| 112 productive of 160 available | 70% | 70% |
| The same machine as the bottleneck | 70% | an extra hour is worth 340 |
| Running very hot | 92.5% | 92.5% — queues will build |
FAQFrequently asked questions
How do I calculate machine utilisation?
Productive hours divided by available hours.
Should I aim for 100% utilisation?
Almost never. Queue times rise non-linearly as utilisation approaches capacity, so a plant running flat out has no ability to absorb variation.
What utilisation should I target?
On non-bottleneck equipment, 70 to 85% typically keeps lead times stable. The bottleneck is the exception.
Why does the bottleneck matter more?
Because an hour lost at the constraint is an hour lost for the whole plant. An hour lost elsewhere is usually free.
Does setup time count as utilisation?
Not as productive time, though it is necessary. Tracking it separately is what makes changeover reduction visible.
Where these figures come from
- Nakajima (1988) — Introduction to TPM — the origin of Overall Equipment Effectiveness and its six big losses
- Health and Safety Executive — the UK workplace safety regulator
Last checked: September 2026. Definitions follow standard operations-management practice; where plants commonly differ, the page says so.