Work out labour days for task instantly with clear inputs, formula shown and shareable results.
Person days come from dividing the quantity by effective output per person per day. Calendar duration is then person days divided by crew size, so the same effort can be spent over a long thin programme or a short heavy one. Labour hours at eight per day feed cost and safety man-hour reporting.
Effort and duration
Person days = quantity / (output x efficiency); calendar days = person days / crew size
Person days = quantity / (output x efficiency); calendar days = person days / crew size. Person days come from dividing the quantity by effective output per person per day.
Safety statistics such as lost time injury frequency rate are expressed per million man-hours, so the hours figure is needed regardless of how the cost is built up.
This calculator takes 4 inputs: Quantity of work, Output per person per day, Crew size, Efficiency factor. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.