A 40 × 50 ft house with a 4/12 gable roof and 12-in overhangs has about 2,302 sq ft of roof — 23 squares. Order 73 bundles of architectural shingles, including 4% waste.
| Item | Covers | Buy |
|---|---|---|
| Starter strip | 193 ft | 2 bundles |
| Hip & ridge cap | 52 ft | 3 bundles |
| Underlayment | 2,302 sq ft | 3 rolls |
| Ice & water | 208 ft | 4 rolls |
| Drip edge | 193 ft | 20 × 10 ft |
| Nails | 6,932 nails | 1 coil box |
| Ridge vent | 52 ft | 13 × 4 ft |
Code runs it from the eave edge to 24 in inside the exterior wall, measured level — counted here from the wall's inside face, as Owens Corning requires. With a 12-in overhang and 6-in wall at 4/12 that is 44 in up the slope → 2 courses of 36-in membrane. Valleys get one 36-in strip centered on the valley line.
Exhaust 960 sq in → 52 ft of ridge vent at 18 sq in per ft (you'd want 53 ft). Intake 960 sq in → 107 ft of continuous soffit vent or 18 16×8 vents. Intake should match or beat exhaust; if your attic qualifies for 1/300 (balanced vents, plus a vapor retarder in climate zones 6–8), halve these.
| Line | Bundles | Est. cost |
|---|---|---|
| Architectural32.8 sq ft per bundle | 73 | $3,284 |
| GAF Timberline HDZ32.8 sq ft per bundle | 73 | $3,284 |
| OC Duration32.8 sq ft per bundle | 73 | $3,055 |
| OC Oakridge32.8 sq ft per bundle | 73 | $2,930 |
| CertainTeed Landmark33.3 sq ft per bundle | 72 | $2,753 |
| IKO Cambridge / Dynasty33.3 sq ft per bundle | 72 | $3,239 |
| Atlas Pinnacle33.3 sq ft per bundle | 72 | $3,239 |
| 3-tab32.3 sq ft per bundle | 75 | $3,224 |
Typical range $9,534–$16,440 · about $5.64 per sq ft of roof
One layer of old architectural shingles ≈ 2.8 tons and 11.5 cu yd. Book a 30-yard dumpster (about 3 tons included). Rentals run $395–$875; shingles hit the weight limit long before the bin is full.
Shelf prices from McCoy's (San Marcos, TX) checked Oct 23, 2026; GAF Timberline HDZ, IKO and Atlas shingles use a typical architectural price. Tap any price to use your supplier's.
| Pitch | Multiplier | Roof sq ft | Squares | Bundles | Ice & water rolls |
|---|---|---|---|---|---|
| 3/12 | 1.031 | 2,251 | 22.5 | 72 | 4 |
| 4/12 | 1.054 | 2,302 | 23 | 73 | 4 |
| 5/12 | 1.083 | 2,366 | 23.7 | 76 | 4 |
| 6/12 | 1.118 | 2,442 | 24.4 | 78 | 4 |
| 7/12 | 1.158 | 2,528 | 25.3 | 81 | 4 |
| 8/12 | 1.202 | 2,625 | 26.2 | 83 | 4 |
| 9/12 | 1.25 | 2,730 | 27.3 | 86 | 4 |
| 10/12 | 1.302 | 2,843 | 28.4 | 90 | 4 |
| 12/12 | 1.414 | 3,089 | 30.9 | 97 | 4 |
With 12-in overhangs the roof covers 42 × 52 ft = 2,184 sq ft of plan. A 4/12 pitch multiplies that by √(1 + (4/12)²) = 1.0541, giving 2,302.1 sq ft. CertainTeed's waste table puts a 2,302 sq ft gable at 4%, so 2,302.1 × 1.04 ÷ 32.8 sq ft per bundle = 72.99, rounded up to 73 bundles.
As a hip roof the surface is the same, but the edges change: 188 ft of eaves and 122 ft of hips need 2 starter and 6 ridge-cap bundles, and the waste allowance rises from 4% to 9% — 77 bundles instead of 73.
Is 2,000 sq ft your living area rather than the footprint? On a two-story house the footprint is about 1,000 sq ft, and the same 4/12 roof drops to about 11.9 squares and 39 bundles. Always measure the outside of the house, one floor.
Ice & water shield: (12 in of overhang + 6 in of wall + 24 in inside it) × 1.054 = 44 in up the slope, so 2 courses of 36-in membrane along 104 ft of eaves — 4 rolls of 65 ft after 6-in end laps.
The full method, material data and tips are on the main roofing calculator page.