How to Measure Exterior Gables and Fascia for Accurate Paint Orders
Exterior gable wall area is calculated using the triangle area formula: Area = 0.5 × Base Width × Peak Height. For example, a gable end that is 28 feet wide at eave height with an 8-foot peak height contains exactly 112 square feet (0.5 × 28 × 8). Two identical gable ends equal 224 sq ft total.
Published 2026-03-01 · Updated 2026-03-01 · 8 min read
Gable Siding Texture and Overlap Multipliers
Once you calculate triangular 2D gable square footage, apply siding texture factors:
• Horizontal Vinyl / Aluminum: 1.05 × flat area.
• Wood Lap / Fiber Cement: 1.15 × flat area.
• Cedar Shakes / Staggered Shingles: 1.25 × flat area.
• Board and Batten: 1.20 × flat area.
Worked Example: 2 Gable Ends with Cedar Shake Siding (30 ft base, 9 ft peak)
Calculating exterior acrylic paint for 2 front/rear roof gable ends with cedar shake texture.
Purchase 3 gallons of exterior satin acrylic paint.
How do you calculate paint for exterior gable vents?
Standard louvered gable vents are painted with trim enamel; allow 1 quart of exterior trim paint for 2 standard 18×24" vents.
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