Capacity Planning Calculator

Workload, units

Hours a unit

Term, weeks

Working hours a week

Useful utilisation, %

Part of the week goes on meetings, switching and handovers.

Current team

Result

People needed5
Exact requirement5
Is the team enoughenter the current team size to compare
Total hours of work1,800
Useful hours per person360
Units per person240

Forty hours a week is not forty hours of work

Calculates how many people a workload needs within a deadline, allowing for the share of the week that is genuinely productive.

The naive calculation divides the total hours by forty and hires accordingly. It always comes up short, because nobody spends a full week on the work itself: meetings, handovers, questions and switching between tasks take their share.

Seventy to eighty percent utilisation is realistic for focused work; below sixty means something is wrong with the process. Putting that percentage into the calculation is the difference between a plan and a wish.

What this calculator shows

The exact and the rounded headcount needed
The total hours of work and the useful hours one person contributes
Whether the team you already have is enough

What to keep in mind

The work is divisible and can run in parallel. Some work cannot, and no headcount shortens it.
New people are assumed to be productive immediately, which is never true. Add ramp-up time to the estimate.

FAQs

What utilisation should I assume?

Seventy to eighty percent for skilled work. Support roles that field interruptions run lower, and anything above ninety is a sign the estimate is optimistic.

Can I halve the schedule by doubling the team?

Rarely. Coordination grows with the square of the team, and work with dependencies has a floor no headcount goes below.

Why round up?

Because you cannot hire four point three people. The fraction is worth knowing, though: 4.1 means a small overtime allowance, 4.9 means hire the fifth.

Does the hours-per-unit figure need to be exact?

It needs to be honest. Use the measured average from past work rather than the time the task takes when everything goes right.

Worked example

Twelve hundred units in twelve weeks

Input: 1,200 units, 1.5 hours each, 12 weeks, 40-hour week, 75 percent utilisation

Output: 5 people

Note: That is 1,800 hours of work against 360 useful hours per person. At a naive 100 percent utilisation the answer would be under four, and the deadline would be missed.

Useful links

All tools in Business and warehouse calculators

Capacity Planning Calculator

Result

Related tools

Meeting Cost Calculator

Employee Cost Calculator

Study Time Planner

Useful links