Capacity Planning Calculator
Whether your capacity meets demand — with utilisation, the headroom left, and how much the queue grows as you approach full.
Capacity is units per period times available time times efficiency.
How the capacity planning calculator works
Capacity is units per period times available time times efficiency. Utilisation is demand over capacity.
The non-obvious part is what happens near 100%. Queueing theory says waiting time rises as 1/(1−utilisation), so a system at 90% has ten times the queue of one at 50%, and at 95% it has twenty. Planning to run at full capacity guarantees delays.
Formula: capacity = rate × hours × efficiency; queue factor = 1/(1−utilisation)
Worked examples
| Inputs | Utilisation | Note |
|---|---|---|
| 850 units against two resources | 109.65% | 110% — over capacity |
| Three resources | 73.1% | 73% — comfortable |
| Higher efficiency | 98.11% | still tight |
FAQFrequently asked questions
What utilisation should I target?
75 to 85% for most operations. Planning for 100% guarantees queues, because arrivals and service times vary.
Why do queues explode near full capacity?
Because waiting time scales as 1/(1−utilisation). At 90% the queue is ten times the idle case; at 95% it is twenty.
What is effective efficiency?
The share of available hours that actually produces output, after setup, breaks, maintenance and rework. 80 to 90% is typical.
Should I add resources or hours?
Whichever is cheaper at the margin. Overtime is faster to deploy and more expensive per unit; hiring is the reverse.
What about demand variability?
This models the average. Peaks matter more — capacity sized to the mean will fail regularly if demand is lumpy.
Where these figures come from
- Corporate Finance Institute — EBITDA — why EBITDA is a non-GAAP measure with no single definition
- US SEC — Non-GAAP Financial Measures, Compliance & Disclosure Interpretations — the disclosure rules that exist precisely because EBITDA is not standardised
- Financial Reporting Council — the UK accounting and audit regulator
Last checked: September 2026. These are standard management-accounting definitions; where a term has no single agreed definition, the page says so.