Crew Size Calculator
Crew needed to hit a deadline given total labor hours and productivity. Plan capacity, not optimism.
From your takeoff or estimate. Total man-hours, not crew-days.
Accounts for breaks, mobilization, weather, rework. Real productive hours = paid hours × this factor. Industry experience puts most construction crews in the 65–80% range.
Crew Size Needed
14
workers, full-time over 21 calendar days
| Calendar weeks available | 3 |
| Work days available | 15 |
| Productive hrs / worker / day | 6.00 |
| Capacity / worker over period (hrs) | 90 |
| Total labor hrs needed | 1,200 |
| Crew capacity (hrs) | 1,260 |
| Slack (hrs) | 60 |
Plan for absences and weather. Add 1–2 workers above the calculated number for sick days, no-shows, and weather risk on outdoor work. The number above assumes everyone shows up every scheduled day.
Estimates only. Productivity, crew size, and schedule depend on real-world conditions; verify with your project's competent supervision.
Methodology: crew size = ceil(total labor hours ÷ (work days × hours per day × productivity factor)). Work days are capped at the number of calendar days in the period. The reverse mode solves the same equation for work days given a fixed crew size.
Frequently Asked Questions
What is a typical construction productivity factor?
Most field studies and contractor experience put effective productivity in the 60–80% range of paid hours. New crews, complex sites, or jobs with frequent rework drop into the 50–60% range. Well-organized, repetitive work (production framing on a tract, drywall on a flat ceiling) can hit 80–85%. A 75% default is a reasonable starting point for typical commercial or residential work.
Why is 100% productivity impossible?
A "paid hour" includes morning stretch, safety talks, walking to the work area, getting tools, breaks, lunch, cleanup, end-of-day put-away, RFIs, waiting for inspections, material handling, and rework. Even a well-run crew loses 20–25% of paid time to non-installing activity. Anyone budgeting at 100% is budgeting to lose money.
How does this differ from a Gantt schedule?
A Gantt schedule plots tasks against the calendar with dependencies. This tool answers a different question: given a fixed deadline and fixed total hours, how many workers do I need? Use it before you build the Gantt — if the crew size is unrealistic for the trade or the site, the schedule itself isn't feasible and the Gantt is fiction.
When should I add overtime vs add crew?
Overtime works for short pushes — a few days to make an inspection or a closeout. Beyond two to three weeks, overtime productivity drops sharply and you pay 1.5× for less than 1.0× output (often referred to in studies as "schedule compression loss"). For longer overruns, adding crew almost always costs less per produced hour, assuming the work has room and supervision can absorb it. Stacking too many trades in the same area produces its own productivity hit, so adding crew is not free either.