Tools you might need next
Calculate paint gallons for walls and ceilings. Enter room dimensions, coats, and coverage rate to get primer and paint gallons with waste allowance.
Estimate primer gallons from surface area and substrate type. Calculate stain-blocking, drywall, and masonry primer for proper paint prep coverage rates.
Estimate deck stain gallons from deck square footage and board type. Calculate semi-transparent or solid stain for rails, steps, and horizontal decking.
Measure each wall. Standard ceiling height 8–9 ft. Subtract doors and windows from gross area.
Area = Sum of Wall Lengths × Height − OpeningsEach vertical strip is a drop. Pattern repeat adds waste when matching — drop length rounds up to repeat multiple.
Drops = ceil(Wall Width ÷ Roll Width); Adjusted Drop = Drop Length + Pattern Repeat WasteDouble rolls typically 57–61 sq ft usable. Divide total drop area by roll coverage with 10% waste.
Rolls = ceil(Total Drop LF ÷ Usable Roll Length)Updated: July 2026
Pattern repeat adds ~12% waste. 8 ft walls need 28 drops — order 7 double rolls for medium repeat pattern.
90 sq ft single wall — 2 double rolls with minimal waste. Verify batch/lot numbers match across rolls.
Small area but large 36″ repeat on 8 ft ceiling — repeat waste dominates. Calculator prevents under-order on small rooms.
Estimate wallpaper rolls including pattern repeat waste before ordering. Enter wall dimensions, roll coverage, and vertical pattern repeat to calculate drops per roll and total rolls needed for each walled room.