Construction Productivity Calculator

Productivity tells you how much work a crew completes per unit of labour, for example square metres of plaster per man-day or cubic metres of excavation per hour. It is the link between quantities in the BOQ and durations in the schedule, and the first number to check when a project falls behind.

How to use it

1. Enter the quantity of work completed and its unit.
2. Enter the crew size and the hours or days worked.
3. Read the productivity rate and compare it with your planned norm.
4. Or enter a planned rate and quantity to estimate the crew size or duration needed.

The formulas

• Productivity = Output quantity / Labour input (man-hours or man-days)
• Duration = Quantity / (Productivity × Crew size)
• Productivity factor = Actual productivity / Planned productivity

Worked example

A crew of 4 masons and 4 helpers completes 96 m² of blockwork in 3 days. Labour input = 8 × 3 = 24 man-days, so productivity = 96 / 24 = 4.0 m² per man-day. If the plan assumed 5.0 m² per man-day, the productivity factor is 0.8, meaning the activity is taking 25% longer than planned. To finish the remaining 400 m² in 10 days at the actual rate, you need 400 / (4.0 × 10) = 10 workers.

What affects productivity

• Material availability and waiting time.
• Weather, working at height and site congestion.
• Rework caused by design changes or poor quality.
• Overtime fatigue: long weeks reduce output per hour.
• Learning curve: repetitive work speeds up over the first cycles.