Shingle roofing calculator
Squares, bundles and every accessory — starter, cap, underlayment, ice & water, flashing, vents, nails, decking and tear-off.
Job
Roof size
Measure by
Roof style
Edges & walls
Auto values come from the roof size — type over them with tape measurements.
Calculated — type to override
Calculated — type to override
Calculated — type to override
Calculated — type to override
Shingles
Calculated — type to override
Nailing
Calculated — type to override
Underlayment & ice barrier
Calculated — type to override
Valleys
Flashing & penetrations
Attic ventilation
Rule
Calculated — type to override
Decking & tear-off
Materials list
| Item | Qty | Unit price | Cost |
|---|---|---|---|
| Shingles | |||
| Shingles15 squares + 10% waste at 3 bundles/square | 50 bundles | $ | — |
| Starter strip156 LF at 105 LF/bundle | 2 bundles | $ | — |
| Hip & ridge cap42 LF at 25 LF/bundle | 2 bundles | $ | — |
| Underlayment | |||
| Synthetic underlayment1,251 sq ft at 1,000 sq ft/roll | 2 rolls | $ | — |
| Ice & water shield252 sq ft: eaves, valleys, extras | 2 rolls | $ | — |
| Plastic cap nails80 per square | 1 boxes (2,000) | $ | — |
| Metal & flashing | |||
| Drip edge156 LF of eaves and rakes, 2 in. laps | 16 pcs (10 ft) | $ | — |
| Penetrations | |||
| Pipe boots | 3 ea | $ | — |
| Exhaust vent caps (bath, kitchen, dryer) | 1 ea | $ | — |
| Roof sealant | 4 tubes | $ | — |
| Ventilation | |||
| Ridge vent42 LF ≈ 756 sq in of exhaust | 11 pcs (4 ft) | $ | — |
| Fasteners | |||
| Coil roofing nails, 1-1/4 in.320 per square (use 1-3/4 in.+ for cap and vents) | 1 boxes (7,200) | $ | — |
| Decking & tear-off | |||
| Dumpster11.3 cu yd, ≈ 1.9 tons — check the weight limit | 1 15-yd haul | $ | — |
How it works
- Roof area = footprint (with overhangs) × pitch factor, or the sum of each plane. A 6/12 pitch adds 11.8%.
- Waste defaults to 10% for simple gables and 15% when there are hips or valleys. Starter, cap and drip edge add laps on top.
- Ventilation follows the IRC: 1 sq in of net free area per 150 sq in of attic floor, or 1/300 when intake and exhaust are balanced — split half intake, half exhaust.
- Add your supplier's unit prices to any line for a cost estimate; tax and markup are optional.
How to measure
- Footprint mode: measure the building's outside walls and the overhang past them, then read the pitch with a level and tape (inches of rise in 12 in. of run) or a pitch app.
- Plane mode: on the roof, measure each plane's eave, its ridge (0 for a triangle) and eave-to-ridge up the slope. Satellite measurements are level (run) — pick “Level”.
- Measure sidewalls along the slope where the roof meets a wall (step flashing), and headwalls where the top of a roof meets a wall.
Estimates only. Coverage, sizes and waste vary by product and job — verify with the manufacturer's specs and your local building code before ordering.
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