Exterior Paint Estimator — Siding & Walls
Free exterior paint estimator: wall area, siding texture and gables into gallons for outside.
Calculations run entirely in your browser — no account needed and nothing is sent anywhere.Try: House perimeter=150, Wall height=10, Exterior doors=2, Windows=12, Coverage per gallon=300, Number of coats=2, Waste factor=15, Siding type=wood → 1500 sq ft, -222 sq ft, 1278 sq ft, Wood, 2, 9.8 gal, 10 gallons
How to use
The exterior estimator works from the house perimeter times the wall height, minus exterior doors and windows. Rough siding absorbs much more paint than smooth siding, so pick the siding type — wood or vinyl, stucco, or brick — to get a realistic number. Coverage drops from about 350 sq ft per gallon on smooth siding to 150 to 200 on brick.
Add gable ends by raising the perimeter or height estimate, since a gable is triangular wall under a pitched roof. Exterior paint needs mildewcides and UV resistance, so use a product made for outside, and plan primer for bare wood or stained siding.
Doors and windows on the exterior are large, so count them carefully — a set of patio doors can remove as much area as a small wall. Trim, shutters and railings are not in this estimate; budget a separate quart or gallon for those details. For a precise figure on a complex facade, measure each wall face and add them, then compare with the perimeter method used here to confirm the two approaches agree before you buy.
FAQ
How is exterior coverage different from interior?
Rough surfaces absorb far more paint. Smooth wood or vinyl siding yields about 300 to 350 sq ft per gallon, stucco about 200 to 250, and brick or masonry only 150 to 200. Pick the siding type above for a realistic number.
Do I count the gable ends?
Yes. A gable is the triangular wall under a pitched roof. Estimate it as half of (width times gable height) and add it to the rectangular wall area. This tool uses perimeter times wall height; add gable area by raising the perimeter or height estimate if your home has large gables.
What paint should I use outside?
Use exterior-grade paint with mildewcides and UV resistance. Interior paint fails quickly outdoors. Primer matters even more on bare wood or stained siding.