Roofing Order Sheet
Measure the footprint from the ground, add the pitch, and check the bundles-per-square on the actual product before you order.
BFCBrilliance · bfcbrilliance.com/tools/roof-shingle-calculator
The roof
- Address
- Date
- Footprint length
- Footprint width
- Pitch
- Slope factor
- ROOF AREA
- Waste %
- SQUARES
- Bundles per square (CHECK WRAPPER)
- BUNDLES
- Supplier
Sections — one row per rectangle, at its own pitch
| Section | Length | Width | Pitch | Slope factor | Roof area |
|---|---|---|---|---|---|
The arithmetic and the units
- Roofing square
- 100 square feet
- Standard asphalt bundle
- about 33.3 sq ft — 3 per square
- Real range per bundle
- about 28-33 sq ft by product
- Specialty / heavy designer
- 4 bundles per square
- Slope factor
- square root of (1 + (pitch/12)²)
- Roof area
- footprint area x slope factor
- 4/12
- slope factor 1.054 — about 5% more area
- 6/12
- slope factor 1.118 — about 12% more area
- 12/12
- slope factor 1.414 — over 40% more area
- Waste, simple gable
- about 10%
- Waste, valleys / hips / dormers
- 15% or more
The separate order lines
- Shingles — bundles, from the calculation
- Bundles-per-square CONFIRMED on the actual product
- Starter strip — along every eave
- RIDGE CAP — linear feet of every ridge and hip (the forgotten one)
- Underlayment — squares
- Ice-and-water shield — if your climate or code requires it
- Drip edge — linear feet of eaves and rakes
- Nails — and the right length for the layer count
- Flashing — around every penetration, chimney and wall
- Vents and boots — counted off the roof, not guessed
- Skip and disposal — a tear-off is heavy
- Local code checked: layers permitted, deck condition, permits
Measure the ground, not the roof
The footprint plus the pitch gives the roof area exactly — footprint area times the slope factor. On a 6/12 roof that is about 11.8 percent more surface than the ground below. There is no reason to get on a simple gable roof with a tape measure, and every reason not to.
Pitch is the hidden cost
A plan view shows the footprint and nothing else. A 12/12 roof over the same building has 41.4 percent more surface than its own footprint — and that is 41.4 percent more shingles, underlayment, felt and labour. It is the single biggest reason two roofs over identically sized houses can be priced very differently.
Ridge cap is the one people forget
It is sold by the linear foot rather than by the square, so it does not appear anywhere in the bundle calculation and it is routinely discovered missing on the last day of the job. Measure every ridge and every hip, and decide before ordering whether you are buying cap or cutting it from three-tab bundles — that choice changes the bundle count.