Crew Hours and Labour Calculator

What this calculator does

A quantity of work, a production rate, a crew size, hours per day, a burdened labour rate and an overhead allowance go in. It returns productive worker-hours, total worker-hours with overhead, crew hours, days, units per crew day, labour cost, cost per unit, and how many days one additional worker would save.

That last figure is the one worth watching, because it shrinks fast and eventually goes negative.

Worker-hours, then crew days

The distinction matters and gets muddled constantly.

Worker-hours is the total labour the job contains. It is a property of the work, and it does not change when you change the crew.

Crew hours is worker-hours divided by crew size — the elapsed time on site.

Days is crew hours divided by the working day.

So 110 worker-hours is 110 worker-hours whether one person takes fourteen days or five people take three. The quantity of labour is fixed by the work; only the schedule and the cost of compression change.

The production rate is everything

Every number on this page derives from one input: units completed per worker-hour.

It is also the input nobody has reliably.

Published rates exist in estimating manuals and they are averages across conditions you do not share. The same task varies by a factor of two or three with:

Crew experience. A crew that has done this exact task fifty times is dramatically faster than one doing it for the first time, and the gap does not close in a day.

Access and conditions. Ground-level open work versus overhead work in a congested ceiling. Weather. Temperature.

Repetition. The tenth identical unit goes far faster than the first, which is why large repetitive jobs beat their estimates and small varied ones do not.

Complexity. Cutting around obstructions, tying into existing work, matching to something already built.

Material handling distance. How far from the truck to the work.

Which produces the single most valuable practice in estimating: record your actuals. After each job, divide the quantity by the hours it genuinely took — including everything. One job’s real number is worth more than a book of tables, and after a handful of jobs you have a rate for your crew doing your work, which is the only rate that predicts anything.

Overhead is not padding

Twenty percent is the default here and it is a realistic floor, not a cushion.

Non-productive time is real time on the clock and includes: mobilisation and demobilisation, setup and teardown, moving between work areas, material handling, breaks, cleanup, waiting on other trades, toolbox talks and safety briefings, and the general friction of a site.

Push it higher for congested sites, work above ground level requiring scaffolding or lifts, frequent relocations, or any job with several trades working in the same space.

Estimates that leave it out entirely are the most common reason jobs that were “five days of work” take seven. The hours were not wrong; the overhead was never counted.

Burdened rate, not wage

Enter the fully burdened hourly cost, not the wage.

Employing someone costs the wage plus payroll taxes, workers’ compensation insurance (which in construction can be a very large percentage), liability insurance, health benefits, paid time off and equipment. The multiplier is commonly 1.3 to 1.6 times the bare wage, and higher in high-risk trades.

A $28 wage is frequently a $40 cost. Estimating at $28 understates labour by a third, and labour is usually the largest line on a construction job.

If you are a self-employed contractor rather than an employer, the equivalent figure comes from the freelance rate calculator — your billing rate has to cover the same overheads whether or not there is a payroll.

The marginal worker

The calculator reports how many days one more person would save, and it is worth watching that number as you increase crew size.

It falls fast. Going from two to three might save two days; three to four saves one; four to five saves half.

And eventually it goes negative in reality, even though the arithmetic keeps showing a positive number. Past a certain crew size for a given work area, people start waiting on each other, on material, and on space. Coordination overhead grows. The workface has a finite length and only so many people fit along it.

This is the jobsite form of the observation that adding people to a late project makes it later. The arithmetic here divides cleanly; physical work does not. Treat large crew sizes on small areas with suspicion.

Choosing units

The unit is whatever your production rate uses, and consistency is all that matters:

• Square feet — drywall, painting, flooring, roofing, sheathing
• Linear feet — trim, fence, pipe, conduit, kerb
• Pieces — fixtures, doors, windows, hangers
• Cubic yards — excavation, concrete placement

Match the unit to how you have historically recorded work. If your notes say “two of us hung 90 sheets in three days,” your unit is sheets and your rate is 1.9 sheets per worker-hour.

What this leaves out

• Material cost. This is labour only.
• Equipment and rental.
• Supervision and management, often a percentage on top.
• The learning curve. First units are slower; large repetitive jobs improve as they go.
• Weather delays and other lost days.
• Overtime premium. The time card calculator covers what hours past the threshold actually cost.
• Sequencing and trade coordination, which on a multi-trade job usually drives the schedule more than any single crew’s production rate.

For the whole-project view, the building cost calculator works from square footage and unit rates, and break-even covers whether the job is priced to make money at all.