Room Size Calculator
Calculate floor area, perimeter, wall area, and volume of a room from its dimensions.
About the Room Size Calculator
Planning furniture layout, flooring, paint, or even HVAC sizing all start from the same basic room measurements. This calculator takes a room's length and width — and optionally its ceiling height — to compute floor area, perimeter, wall area, and total volume all at once.
How It Works
The calculator multiplies length by width for floor area, adds all four sides together for perimeter, and — if you provide a ceiling height — multiplies perimeter by height for total wall area and multiplies floor area by height for room volume.
Floor Area = L × W; Perimeter = 2(L + W); Wall Area = Perimeter × Height; Volume = Floor Area × Height.
Example
Scenario: A 14ft × 11ft room with a 9ft ceiling.
Result: Floor area of 154 sq ft, a perimeter of 50 ft, wall area of 450 sq ft, and a volume of 1,386 cubic ft.
Assumptions & Limitations
- Assumes a simple rectangular room shape without alcoves, bump-outs, or irregular walls.
- Height is optional since floor area and perimeter alone are useful for many purposes, like flooring or baseboard estimates.
- For irregular room shapes, break the room into rectangular sections, calculate each separately, and sum the results for an accurate total.