Construction schedule calculator for man-hours and crew size
Turns a man-hour estimate into work days, calendar days and a finish date, after crew size, the working week, public holidays and a weather buffer.
Construction schedule calculator for man-hours and crew size: run the calculator
Turn man-hours into a phase duration
Every field is filled in, so the result below is already worked through. Change any figure and the arithmetic follows.
Work days and calendar days
42 work days, 8.4 calendar weeks, finished on Thursday, October 29, 2026.
- 4 people × 8 hours = 32 man-hours produced on one working day.
- 1,200 man-hours ÷ 32 = 37.5 net work days.
- Buffer of 10 percent: 37.5 × 1.1 = 41.3, rounded up to 42 work days.
- The span picks up 1 of the 8 public holidays in a year.
- Together that fills 43 weekday slots in a five-day week.
- Starting Tuesday, September 1, 2026, that runs to Thursday, October 29, 2026: 59 calendar days, 8.4 calendar weeks.
How work days become calendar days
man-hours ÷ (crew size × hours per day) = net work days; × (1 + buffer) and rounded up = scheduled work days; laid on the working week from the start date and lengthened by the holidays inside the span = calendar days and the finish date.
The calculator schedules one phase. A real program has trades that overlap, a crew that moves between them and a delivery date that shifts the whole chain, and that is what the schedule inside Home Builder Software holds.
Construction schedule calculator for man-hours and crew size: what it answers
A phase duration starts as a quantity of labor, not as a date. Once an estimate says how many man-hours a trade needs, the schedule follows from three decisions: how many people stand on that face of work, how many hours each of them produces per day, and how many days a week the site runs. This calculator makes those three decisions explicit and turns them into work days, calendar days and a finish date.
Work days and calendar days are different quantities, and mixing them is the common scheduling error. Forty-two work days on a five-day week already span more than eight weeks before a single public holiday is counted. Enter the man-hours for one trade, read the finish date, then use that date as the start of the next trade. Chaining the phases this way gives a program that survives contact with the site.
Construction schedule calculator for man-hours and crew size: how the result is worked out
Crew size multiplied by hours per person per day gives the man-hours a crew produces in one working day. The man-hour estimate divided by that figure gives net work days. The buffer percentage is applied to the net figure and the result is rounded up, because half a work day cannot be scheduled. Public holidays are then spread across the span at the annual rate you enter, and the weekends of the chosen working week are added on top.
The number that decides everything is hours per person per day. Eight paid hours are rarely eight hours of production once travel, setup, material handling and clean-up are taken out, so a figure between six and seven often matches the timesheets better. Check it against your own time records before trusting the finish date. The second trap is crew size: doubling the crew on a face of work that only fits four people does not halve the duration.
Construction schedule calculator for man-hours and crew size: what the result assumes
The man-hour figure is yours. This calculator does not estimate labor content; it converts a number you already hold from a takeoff, a subcontractor quote or your own job history.
Public holidays are distributed evenly across the span rather than placed on real dates, so the finish date is an estimate. The federal list runs to eleven days; most site calendars observe fewer, which is why the field starts at eight and stays editable.
Weather, inspections, deliveries and access all sit inside the one buffer percentage. Ten percent is a starting point, not a measured value, and a winter foundation carries a different risk from a summer fit-out. The buffer covers whole days lost; the hours-per-day field covers time lost inside a day, so keeping them apart stops the same loss being counted twice.
Every day of the working week counts the same. Shortened Fridays, shift work and overtime windows have to be folded into the hours-per-day figure before the result means anything.
Construction schedule calculator for man-hours and crew size: questions and answers
How many man-hours does it take to build a house?
There is no single figure that transfers between projects, because it depends on the construction method, the level of prefabrication and the finish. Use hours recorded on your own completed projects, or the labor lines of a takeoff. This calculator converts whatever figure you trust into days; it does not produce the figure.
What is the difference between work days and calendar days?
A work day is a day the crew is on site and producing. A calendar day is any day on the calendar, weekends and holidays included. Contracts usually state completion in calendar days while an estimate produces work days, and the gap between the two is roughly forty percent on a five-day week.
How do I turn phase durations into a full construction schedule?
Run the calculator once per trade, using the finish date of one trade as the start date of the next where they cannot overlap. Where two trades share the building, start the second one part-way through the first and take the later of the two finish dates. Home Builder Software keeps that dependency chain per project.
Construction schedule calculator for man-hours and crew size: use it on your own projects
Inside Home Builder Software the same calculation reads the project file, so the figure carries the budget, the awards and the invoices behind it instead of asking you to retype them.