Hip Roof Calculator
Enter your footprint and pitch to get a hip roof's area, eave / ridge / hip lengths, and a complete material list — plus the hip rafter length you'll cut to.
Dimensions
Roof Area
1,342 sq ft
Roofing Squares
13.4
Footprint
1,200 sq ft
Ridge Height
7.5 ft
Edge Lengths (linear ft)
- Eaves140.0
- Rakes—
- Ridges10.0
- Hips90.0
- Valleys—
| Material | Qty | Unit |
|---|---|---|
Architectural field shingles 4 bundles/square × 13.4 squares + 10% waste | 60 | bundles |
Hip & ridge cap Along 100 lf of ridges + hips (~25 lf/bundle) | 4 | bundles |
Starter strip Along 140 lf of eaves + rakes (~100 lf/bundle) | 2 | bundles |
Synthetic underlayment 1000 sq ft/roll, +10% overlap | 2 | rolls |
Drip edge Along 140 lf of eaves + rakes | 14 | 10 ft pieces |
Ice & water shield 420 sq ft band (eaves/valleys), 200 sq ft/roll | 3 | rolls |
Roofing nails ~4,723 nails (320/square), 7,200/box | 1 | coil boxes |
💡 Edge lengths are derived from your dimensions assuming equal pitch on all planes. Complex roofs (dormers, multiple wings) add valleys — measure those separately. Confirm product coverage and order extra for cuts.
Estimates only. See how this calculator works — the formulas, assumptions, and sources behind it.
How Hip Roof Area Is Calculated
A hip roof slopes down to all four walls, so it has four planes meeting at hips and a shorter ridge than the building length. Despite the extra planes, the total surface area is the same as a gable of equal footprint and pitch: footprint × pitch factor. Find your pitch factor with the roof pitch calculator, or trace an irregular footprint with the draw roof tool.
Hip Roof vs Gable: What Changes
- •Same field area for the same footprint and pitch — but a hip needs hip & ridge cap along four hips, not just the ridge.
- •More waste — angled cuts at every hip push the waste factor to 15%+ (vs ~10% for a gable).
- •No rakes or gable ends; the ridge is shorter (longer side − shorter side).
- •Hip rafters run diagonally and are longer than common rafters — see below.
Hip Rafter Length
Each hip rafter runs from a corner to the end of the ridge. Its length is √((span ÷ 2)² × 2 + rise²), where rise = (span ÷ 2) × (pitch ÷ 12). For a 30 ft span at 6:12, rise = 7.5 ft and each hip rafter ≈ 22.5 ft. The calculator's Hips figure is the total of all four. For common rafters and cut angles, use the rafter length calculator.
Hip Roof FAQ
- How do I calculate hip roof area?
- Multiply the footprint (length × width the roof covers) by the pitch factor for your slope. A hip roof's total surface is the same as a gable of equal footprint and pitch — the difference is that a hip splits that area across four sloped planes instead of two. For a 40 × 30 ft footprint at 6:12 (pitch factor 1.118), that is 1,200 × 1.118 ≈ 1,342 sq ft, or about 13.4 roofing squares.
- Does a hip roof use more material than a gable?
- The field shingle area is the same for the same footprint and pitch. A hip roof costs more because it has four hips that each need cap shingles and produce angled offcuts, so budget a higher waste factor — 15% or more versus about 10% for a simple gable. A hip also has no gable ends or rakes, and its ridge is shorter (length minus width).
- How long are hip rafters?
- A hip rafter runs diagonally from each corner up to the end of the ridge, so it is longer than a common rafter. The length is √((span ÷ 2)² × 2 + rise²), where rise = (span ÷ 2) × (pitch ÷ 12). For a 30 ft span at 6:12, rise = 7.5 ft and each hip rafter is √(15² × 2 + 7.5²) ≈ 22.5 ft. The calculator's Hips total is four of these.
- What waste factor should I use for a hip roof?
- Use about 15% for a standard hip roof, and 18–20% if it also has valleys, dormers, or many small planes. The four hips force diagonal cuts on every course, which creates more offcut waste than the straight courses of a gable roof.
- How do I measure a hip roof?
- Eaves run the full perimeter (2 × length + 2 × width). The ridge runs along the top and equals the longer side minus the shorter side. Each hip runs from a corner to the nearest ridge end. Enter the footprint length, width, and pitch and the calculator derives the eave, ridge, and hip lengths for you.