Calculate floor and ceiling area, room perimeter, gross and net wall area, volume, multiple-room totals, opening deductions, known-area conversions, or a missing rectangular dimension.
Room dimensions are normalized to meters before shared geometry helpers calculate area, perimeter, wall area, deductions, and volume.
Height is optional. Without height, floor area, ceiling area, and perimeter remain available while wall area and volume are intentionally omitted.
length × width2 × (length + width)perimeter × heightgross wall area − door, window, and other deductionslength × width × heightknown floor area ÷ known horizontal dimensionA 12 × 15 × 8 ft room has 180 ft² floor and ceiling area, 54 ft perimeter, 432 ft² gross wall area, and 1,440 ft³ volume.
Subtracting one 3 × 7 ft door and two 3 × 4 ft windows from 432 ft² gross walls produces 387 ft² net wall area.
A 300 ft² rectangular room with a known 20 ft length has a calculated width of 15 ft.
A 5 × 4 × 2.5 m room has 20 m² floor area, 18 m perimeter, 45 m² gross walls, and 50 m³ volume.
Leave it blank for floor, ceiling, and perimeter calculations only.
Doors and windows are not subtracted unless their dimensions and quantities are entered.
Follow related links for flooring, paint, drywall, or insulation estimates rather than assuming material coverage here.
Each room keeps its own dimensions, height, openings, and quantity. Floor area and available volume or wall values are aggregated at full precision.
The perimeter total is labeled combined room perimeters; it is not an exterior perimeter for connected rooms.
Opening areas use width × height × quantity. Deductions must remain below gross wall area.
Known-area mode converts area only. Reverse mode assumes a rectangle and divides known area by one supplied horizontal dimension. No square-room assumption is made.
Optional price can apply to total floor area or available net wall area, per square foot or square meter. It reflects only the price entered.
Multiply length by width for floor area and add height when wall area and volume are needed.
Multiply room perimeter by height, then optionally subtract entered openings.
For a simple rectangular room, yes.
Only when the intended estimate requires net wall area; this calculator never subtracts them automatically.
For a rectangular room, divide known floor area by the known length or width.
Add a room card for each distinct size and use quantity for identical rooms.
It provides source measurements; use the related dedicated material calculators for product estimates.