Free US quantity worksheet
Hip Roof Calculator for a Simple Rectangular Roof
Enter the building footprint, equal horizontal overhang and common rise per 12 inches. The model calculates roof surface area and geometric distances for a rectangular roof with equal pitch on every side. It does not supply rafter cut lengths or framing design.
Starting figures illustrate the calculation. Replace them with verified measurements and the actual product details. Allowances are your choice, not a recommended rate.
Your quantity result
- Sloped roof surface area (sq ft)
- 523.24
- Horizontal area including overhang (sq ft)
- 468
- Roofing squares before allowance (100 sq ft)
- 5.23
- Geometric ridge length (ft)
- 8
- Height from eave plane to ridge (ft)
- 4.5
- Common slope distance (ft)
- 10.06
- Each hip slope distance (ft)
- 13.5
Rectangular footprint, equal pitch on every side and equal horizontal overhang. Lengths are geometric surface/centerline distances, not cut lengths. No ridge-board deductions, structural sizing, openings, waste or roof-detail takeoff.
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How the simple hip-roof geometry works
The footprint grows by twice the overhang in both directions. The tool uses the longer expanded side as length L and shorter side as width W. The horizontal run is W / 2 and the pitch ratio p is the entered rise / 12.
Roof surface area = L × W × √(1 + p²). The geometric ridge is L - W, common slope distance is (W / 2) × √(1 + p²), and each hip slope distance is (W / 2) × √(2 + p²). The height above the eave plane is (W / 2) × p.
For a 24 ft by 16 ft footprint with no overhang and 6:12 pitch, the ridge is 8 ft, height is 4 ft, common slope distance is about 8.944 ft, each hip distance is 12 ft and roof surface area is about 429.325 sq ft.
Keep surface geometry separate from construction dimensions
All four roof planes share the same pitch. A square footprint has a point at the top rather than a positive ridge length in this model. The tool does not cover unequal pitches, intersecting roofs, dormers, valleys, openings or multiple roof levels.
Distances do not deduct ridge or hip-board thickness or account for cuts, bearing, connectors or overhang construction. Area excludes material laps and chosen waste. Verify the roof layout and appropriate design before ordering materials or using a dimension for work.