Which entry mode should I use?
Use sequential wall-by-wall entry for a straightforward rectangular or simple room, or polygon vertices for an irregular shape.
Room Layout Calculator
Calculate polygon area, perimeter, and wall area.
This room has — sq ft of wall and — sq ft of floor.
Room dimensions
Rectangle entry is converted to ordered polygon vertices.
Openings
Doors, windows and pass-throughs are subtracted from the wall area. Leave this empty only if the room really has none — an empty list is read as a room with no openings, and the wall area chains onward to Drywall, Insulation, Paint and Wallpaper.
This room has — sq ft of wall and — sq ft of floor.
This room has
Room Layout results
Detail values
- Perimeter
- — ft
- Wall area (gross, no openings entered)
- — sq ft
- Wall segments
- ft
Assumptions
- Opening deduction: None entered - wall area is gross
Included: floor area, wall area, perimeter, wall segments, deduction of the openings you enter.
Not included: labor, permits, engineering review or stamped plans, fasteners and connectors unless explicitly itemized above.
Formula details
- Floor area: 0.5 x abs(sum(xi x yi+1 - xi+1 x yi))
The shoelace (surveyor's) formula for the area of a simple polygon, wrapping the last vertex to the first; the perimeter is the Euclidean distance summed around that same closed list. Both are mathematical identities -- no trade convention and no published source stands behind either, and none is needed.
Material List
About this calculator
Use room dimensions, either as polygon vertices or sequential wall-by-wall entry, to feed downstream Drywall, Paint, Flooring, and Trim material estimates.
FAQ
Do openings subtract from wall area?
Yes. Door and window openings you enter are subtracted from the total wall area before it is passed to other calculators.
Can I send this area straight to Drywall or Paint?
Yes. Floor area, wall area, and perimeter from Room Layout can be used directly by Drywall, Paint, Flooring, and Trim instead of re-entering measurements.
Disclaimer
General measurement reference; verify field dimensions before ordering material.