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Capacity Planning Calculator

Work out the headcount needed to deliver a workload at a realistic utilisation rate.

About Capacity Planning Calculator

Rated capacity is a ceiling, not a design point, so it is derated by the headroom percentage before dividing. The result is rounded up because you cannot deploy a fraction of a person. Sizing to rated capacity leaves nothing for peaks or failures; the spare-capacity line shows whether the rounded-up count actually buys useful delivery capacity.

Formula

Capacity Planning

Units = ⌈demand ÷ (capacity per unit × (1 − headroom))⌉

Total hours of work to deliver
Total load to be served
Productive hours per person
Rated capacity of a single person

Worked example

With the default values below, Capacity Planning Calculator returns Persons Required of 20. Change any input above and every figure here is recalculated in your browser.

Inputs used

Total hours of work to deliverminimum 0
24,000
Productive hours per personminimum 0
1,450
Headroom reserved for peaksaccepts 0–100 %
15 %

Results

Persons Required
20
Exact Requirement Before Rounding
19.473
Usable Capacity per Person
1,232.500
Spare Capacity at That Count
2.6%
Total Usable Capacity Provisioned
24,650.00

Step by step

  1. 1Values used
  2. 2Capacity Planning
  3. 3Persons Required= 20
  4. 4Exact Requirement Before Rounding= 19.473
  5. 5Usable Capacity per Person= 1,232.500
  6. 6Spare Capacity at That Count= 2.6
  7. 7Total Usable Capacity Provisioned= 24,650.00

Assumptions and limits

  • The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Capacity Planning calculated?

Units = ⌈demand ÷ (capacity per unit × (1 − headroom))⌉ Rated capacity is a ceiling, not a design point, so it is derated by the headroom percentage before dividing. The result is rounded up because you cannot deploy a fraction of a person.

Why does Capacity Planning matter?

Sizing to rated capacity leaves nothing for peaks or failures; the spare-capacity line shows whether the rounded-up count actually buys useful delivery capacity.

What values do I need to enter?

This calculator takes 3 inputs: Total hours of work to deliver, Productive hours per person, Headroom reserved for peaks. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

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