A crew-day is one full crew assigned to one job for one working day. The number of crew-days a job needs is the install work divided by the hours the crew actually spends on site each day, after the drive, rounded up.
The formula
Crew-days = Install hours ÷ (Shift hours − Round-trip drive hours), rounded up
Paid crew hours = Crew-days × Shift hours × Crew size
The install hours come from your estimate for that job: the labor the work itself needs with the whole crew on it. The shift is what you pay. The drive is the round trip from wherever the crew starts to the site, and it comes off the top of every day the crew spends there.
Rounding up matters. A job that needs 1.2 crew-days of work occupies two crew-days on the board, because a crew cannot start a second job that afternoon unless something else is close enough to reach.
A worked example
This is illustrative. A three-person crew works a 10-hour shift. The job needs 15 hours of install work.
Same roof, same panels, same crew. The distance alone added a crew-day and 30 paid person-hours. That is why the solar install page treats the morning drive as the main scheduling risk on a crew job.
Why the crew-day is the right unit
Install trades rarely run out of hours. They run out of whole days. A board that counts person-hours shows capacity that a crew cannot use, because a three-hour gap at the end of day two is only useful if there is a three-hour job nearby. Counting in crew-days makes three things visible:
- Distance has a price. Far sites cost more crew-days for the same work, so they should be priced and dated that way.
- Partial days are the leak. The fraction after the decimal is where crews end up driving home at 1:00 p.m.
- Subcontracted crews are sold this way too. When you hire a sub crew, you are usually buying crew-days, which is how solar and roofing subcontractor scheduling gets planned.
A common mistake
Estimating crew-days from install hours alone and ignoring the drive. The estimate is right at the shop and wrong at the site. Put the round trip into the formula for every job, and use your recorded drive time at the hour the crew actually leaves, not a map distance.
For how crews get placed on the board once the crew-days are known, see crew scheduling.
What to take away
- A crew-day is one crew on one job for one working day.
- Crew-days = install hours ÷ (shift hours − round-trip drive), rounded up.
- A long drive can add a whole crew-day to the same job.
- Price and date far sites in crew-days, not install hours.
Common questions
How do you calculate crew days for a job?
Take the job's install hours and divide by the hours the crew will spend on site each day, which is the shift minus the round-trip drive. Round up to the next whole day.
Is a crew-day the same as a man-day?
No. A man-day (or person-day) is one person for one day. A crew-day is the whole crew for one day, so one crew-day for a four-person crew is four person-days.
Should a crew-day include drive time?
The paid crew-day does, because you pay the crew while it drives. The productive part of the crew-day does not. Track both so you can see how much of each crew-day the drive is taking.