Construction Labour Requirement Calculator

Work out construction labour requirement instantly with clear inputs, formula shown and shareable results.

About Construction Labour Requirement Calculator

Labour demand is total effort divided by available time. Effort in person days is the quantity divided by effective daily output, where effective output is the nominal norm reduced by a site efficiency factor covering weather, waiting and rework. Dividing by the programme duration gives the crew size.

Formulas

Effort

Person days = quantity / (norm output x efficiency)

Crew size

Workers = ceil(person days / duration)

Worked example

With the default values below, Construction Labour Requirement Calculator returns Workers required of 5. Change any input above and every figure here is recalculated in your browser.

Inputs used

Quantity of workminimum 0.1 units: 500 units
Output per person per dayminimum 0.01 units: 12 units
Available durationminimum 0.5 days: 10 days
Site efficiencyaccepts 20–100 %: 85 %

Results

Workers required: 5
Person days of effort: 49.0 person·days
Effective output per person per day: 10.20 units
Duration with the rounded crew: 9.80 days

Step by step

1Values used
2Effort
3Crew size
4Workers required= 5
5Person days of effort= 49.0 person·days
6Effective output per person per day= 10.20 units
7Duration with the rounded crew= 9.80 days

Assumptions and limits

The result is derived only from the 4 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 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

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 the Construction Labour Requirement figure worked out?

Person days = quantity / (norm output x efficiency). Labour demand is total effort divided by available time.

Can I halve the duration by doubling the crew?

Rarely. Beyond a certain density workers interfere with each other and productivity per head falls, so crowding a trade usually gives less than proportional gain.

What values do I need to enter?

This calculator takes 4 inputs: Quantity of work, Output per person per day, Available duration, Site efficiency. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.