Hip Roof Calculator
A hip roof slopes on all four sides. The calculator is set to a hip roof: for the default house it finds 1,409 sq ft of roof, a 12 ft ridge and four hips of 22.5 ft each.
- Roof area1,409 sq ft
- Ridge12 ft
- Each hip22.5 ft
- Cap length102 ft
Bundles of shingles
47 bundles
15.50 squares with 10% extra × 3 bundles
Buy 47 bundles of shingles, plus 2 starter and 5 ridge cap.
- Roof area1,409 sq ft (130.9 m²)
- Squares14.09
- Squares with extra15.50
- Starter strip bundles2 (144.0 ft, estimated)
- Ridge cap bundles5 (102.0 ft, estimated)
- At your price per bundleAdd a price
Field shingles come from the area and your extra. Starter (about 120 ft per bundle) and ridge cap (about 25 ft per bundle) come from the edge lengths; leave them blank to use a simple gable or hip estimate.
Planning estimate, not a quote. Disclaimer
How a hip roof is measured
A hip roof meets the walls on four sides, with a short ridge and four hip rafters running from the corners up to the ridge ends. Roof area is the same as for a gable roof with the same footprint, overhang and pitch: footprint times the pitch multiplier. What changes is the edge length. There are no rakes, so the starter strip runs along the eaves only, and the ridge cap covers the ridge plus the four hips.
Hip length = (width ÷ 2 + overhang) × √(2 × 12² + rise²) ÷ 12
Cap length = ridge + 4 × hip length
Starter = eaves all around
Example: a 40 × 28 ft house with a 12-inch overhang at 6/12. The ridge is 12 ft. Each hip runs 22.5 ft (a 15 ft run times 1.50). Ridge plus four hips is 102 ft of cap, 5 bundles at 25 ft per bundle. The eaves are 144 ft, 2 bundles of starter.
Hip roof sizes at 6/12
| Footprint | Ridge | Each hip | Cap length | Cap bundles |
|---|---|---|---|---|
| 30 × 20 ft | 10 ft | 16.5 ft | 76 ft | 4 |
| 40 × 28 ft | 12 ft | 22.5 ft | 102 ft | 5 |
| 50 × 30 ft | 20 ft | 24.0 ft | 116 ft | 5 |
| 60 × 36 ft | 24 ft | 28.5 ft | 138 ft | 6 |
The table assumes a plain rectangle with the same pitch on every side. L-shaped and cross-hipped roofs have valleys and extra ridges: measure each part and add them. Hips and valleys also waste more shingle, so use 12 to 15% extra. The hip rafter factor matches the rafter calculator.
Frequently asked questions
How do you calculate the area of a hip roof?
Multiply the footprint, including overhang, by the pitch multiplier. It is the same as a gable roof with the same footprint, overhang and pitch.
How long is a hip rafter?
The common run times the hip/valley factor. For a 15 ft run at 6/12 the factor is 1.5000, so the hip is 22.5 ft.
How do I find the ridge length of a hip roof?
Building length minus building width, for a rectangle with equal pitch on all sides. A 40 × 28 ft house has a 12 ft ridge.
How many bundles of ridge cap does a hip roof need?
Divide the ridge plus hip length by 25 ft per bundle. The example needs 102 ft, which is 5 bundles.
Do hip roofs use more shingles than gable roofs?
The surface is the same, but hips add cut waste and more cap. Plan for 12 to 15% extra.
Related
Other roofing calculators
Sources
- GAF Seal-A-Ridge listing (25 lineal ft per bundle, 45 pieces) (checked Nov 12, 2026)
- GAF: Pro-Start starter strip shingles (checked Nov 12, 2026)
- Swanson Tool: Roof pitch reference (rafter length per foot of run) (checked Nov 12, 2026)