← Skylight install bid calculator
Homeowners call with a box already in the garage: “I found one on Amazon for $180. Can you just install it for $350?” That reads as free margin because the unit invoice left the bid. It did not take the pull, the cut, the flashing, or the chance that a boxed unit is sized for a curb you do not have.
Open the free skylight install bid calculatorA contractor-supplied tubular replace on asphalt, one story, still carries the unit and flashing invoices along with the labor. An owner-supplied unit that actually fits zeros those two material lines and keeps the same pull, cut, and site hours. On a typical cheap special — $42 wage, 30% burden, 15% overhead, 20% target margin, 8 miles — the contractor-supplied walk-away is about $1,018. Zeroing the unit and flashing invoice drops that to about $483, but a $350 install-only ask still loses about $133 once labor, travel, and overhead are counted. A unit that turns out to be the wrong size adds an inspect trip and a hardware kit, and the walk-away climbs back to about $646 — the $350 ask now loses about $296.
| You supply | They supply, it fits | They supply, wrong unit | |
|---|---|---|---|
| Unit and flashing invoice in the bid | Yes | No | No |
| Pull, cut, and site hours | Same | Same | Same, plus an inspect trip |
| Walk-away on the cheap special | About $1,018 | About $483 | About $646 |
| At $350 install-only | Loses | Still loses | Loses more |
Online listings skip the curb measurement and the roof pitch. Boxes come sized for a curb-mount opening when the roof needs a deck-mount kit, or a tubular kit shows up missing the diffuser or the right run of tubing. Setting the wrong unit means a second dispatch plus flashing or hardware they expect you to eat. Price that callback on the same opening before you agree. The numbers above add a second inspect trip and a small hardware kit on top of the rates you already typed.
Open the skylight install bid calculator, enter the opening you are standing on, zero the unit and flashing invoices, and put their install-only number in “price you’re considering.” Compare the walk-away price you get against you-supply, owner-supplies-it-fits, and owner-supplies-wrong-unit. Nothing is uploaded.
This is the same arithmetic as how much to charge to install a skylight. It is not a building-code determination, a manufacturer warranty question, or a reason to refuse a customer — it is the walk-away number on each supply path.
Only after you price the job without the unit and flashing invoices. The labor, the cut or pull, the roof flashing, and overhead do not zero out. A $350 install-only special often sits under that walk-away number even when the unit itself cost you nothing.
Usually not. Zeroing the unit and flashing invoice drops the bid a lot on a cheap tubular unit, but loaded labor, roof flashing, travel, and overhead stay. On a typical replace-existing tubular job the owner-supplied walk-away is still well above a $350 install-only ask.
That is a second trip plus a hardware or flashing kit they did not budget for — a boxed unit sized for a different curb, or a tubular kit missing the right diffuser. Price that callback on the same opening before you agree to install whatever showed up in their garage.