Material coverage & waste factors

These are the coverage and waste conventions the calculators use — labeled planning bands, not a price list. Coverage varies by product, so check your product label; waste varies by layout. Use the painting, drywall, flooring and tile tools to apply them.

MaterialCoverage / wasteNotes
Interior paint~350–400 sq ft / gallon / coatBy product & surface porosity
Drywall (4×8)32 sq ft / sheetFixed sheet size
Tilearea × (1 + 10–15% waste)Higher for diagonal / pattern
Flooringarea × (1 + 7–12% waste)Higher for complex rooms
Trim / baseboardperimeter × (1 + ~10% waste)Round up to whole linear feet

Labeled planning bands — check your product label and your quote. Quantity = area ÷ coverage × (1 + waste).

Related calculators

Interior Painting Cost & PaintEstimate interior painting cost and how much paint you need: enter room size, coats and your paint price to get wall area, gallons and the total.Drywall Sheets & CostWork out how many 4x8 drywall sheets and the cost for a room: enter wall and ceiling area, your price per sheet, mud and tape, and any labor.Flooring Cost by MaterialEstimate flooring cost by material and how much to order: enter the area, pick a waste factor, and add your material and install price per sq ft.Tile Installation CostEstimate tile installation cost and how much to order: enter the area, choose a waste factor, and add your tile price and labor per square foot.