How to Measure Walls for Paint
Measure walls, openings, coats, and waste before using a paint calculator.
Measure room dimensions
Measure the length and width of the room, then measure wall height from finished floor to ceiling. For a rectangular room, wall area is 2 x (length + width) x wall height.
Subtract large openings
Standard doors and windows reduce paintable wall area. Exact openings are best, but rough standard sizes are enough for an early shopping estimate.
Choose coats and waste
Most interior color changes need two coats. Add 5-15% waste for spills, touch-ups, textured surfaces, and future repairs.
Check the paint label
Coverage varies by brand, sheen, color, and surface. Use ProjectYard for planning, then compare against the label before purchase.
FAQ
Do I need exact door and window sizes?
Exact sizes improve the estimate, but standard sizes are enough for a first shopping list.
Should I include closets?
Include closets when they will be painted with the same wall paint.
How much waste should I add?
Use 10% for most rooms and more for textured walls or heavy repairs.
Project planning hub
Plan interior paint by measuring walls, ceilings, trim, coats, primer, coverage, and waste before buying.
Paint Project Planning GuideRelated guides
Next step
Open the calculators and enter your dimensions to estimate materials before you shop.