Master Room Calculator
How much paint, wallpaper and tile do you actually need, before you buy. Enter your measurements below.
Paint coverage: 350 sq ft per gallon. Doors allow 21 sq ft each, windows 15 sq ft each. Primer is estimated for one coat.
Strips allow 0.5 ft trim at the top and bottom. Wastage is applied to the wall width before counting strips.
Boxes use 10 tiles per box for 12×12, 8 per box for 12×24, and 4 per box for 24×24.
AC size uses a baseline of 20 BTU per sq ft. Fan size is based on room area only.
How to Measure Your Room Accurately
Use a tape measure, not a guess. Measure each wall from corner to corner in feet, and measure ceiling height from floor to ceiling. For floors, measure length and width at the longest points. Write down doors and windows, count them, and re-measure once before you buy. Remember: all calculator results are estimates, so double-check with a tape measure or contractor before buying
materials.
FAQs
How accurate are the calculators? They are estimates based on standard coverage and wastage, so always double-check before buying. How much paint covers a gallon? This calculator uses 350 sq ft per gallon. Do I need primer? Primer is estimated for one coat and helps on new or patched walls. How much extra tile should I buy? Choose 5 to 15 percent wastage for cuts and breakage.