Room materials calculator: measure once, shop once
Redoing a room usually means paint, flooring and new baseboard, and sometimes drywall. Enter the room's size here once and see all four amounts together, instead of typing the same numbers into four calculators.
- 4 materials at once
- Doors and windows taken out
- Waste included
Assumes a rectangular room, 2 coats of paint at 350 sq ft per gallon, 4x8 drywall sheets, and 16-foot baseboard pieces. For textured walls, different sheet sizes or tile, use the full calculators linked in each result.
Do the job
How it works
Wall area = 2 × (length + width) × height, minus about 20 sq ft per door and 15 sq ft per window. That's what paint and wall drywall are based on.
Paint = wall area (plus the ceiling if you tick it) × 2 coats ÷ 350 sq ft per gallon, rounded up to whole gallons, or to quarts for a small room.
Flooring = length × width + 10% for cuts, divided by the square feet in a box and rounded up.
Baseboard = the room's perimeter, minus about 3 feet per door, + 10%, in 16-foot pieces.
Drywall = wall area + 10% for waste ÷ 32 sq ft per 4x8 sheet, rounded up, with the ceiling added separately if you tick it.
About this tool
Who it's for
For a bedroom or living room makeover where you're buying several materials for the same room.
Example
You enterA 12 x 12 room, 8 ft walls, 1 door, 2 windows
You getAbout 2 gallons of paint, 8 boxes of flooring, 4 pieces of baseboard, 12 sheets of drywall.
What's different
- One set of measurements for four materials.
- Uses the same math as our separate calculators.
- Each result links to the full calculator for more options.
Gotchas and tips
- Measure at the floor for baseboard and flooring; walls aren't always straight.
- Closets count: add their walls and floor.
- Buy flooring and paint from the same lot so the color matches.
Privacy: Runs entirely in your browser. Nothing you type is sent to us.
Built and maintained by the GrabTheHammer team, using the same math as our paint, flooring and drywall calculators. Updated November 2026. Spot a problem? Tell us.
Room materials questions
Do I need to subtract doors and windows?
For paint and drywall, yes, and the calculator does it: about 20 square feet per door and 15 per window. For baseboard it takes about 3 feet off per door. Windows don't change the flooring.
Why is there extra on everything?
Cuts, mistakes and odd corners. Flooring and baseboard get 10% extra, drywall gets 10% for waste, and paint is rounded up so you don't run out halfway through a wall.
Can I use this for an L-shaped room?
Split it into two rectangles, run each one, and add the results. For paint, the shared edge between the two isn't a wall, so the total will run a little high, which is usually fine.