Room Area Calculator

Calculate floor square footage, perimeter, and area breakdowns for rectangular or L-shaped rooms.

Formulas & Calculation Methodology

Floor area determination depends on the geometric shape of the room. For standard rectangles, floor area equals length multiplied by width. For L-shaped rooms, the area equals the bounding rectangle minus the non-overlapping corner cutout.

  • Rectangular Room: Area = Length × Width | Perimeter = 2 × (Length + Width)
  • L-Shaped Room (Cutout): Area = (L × W) - (l × w) | Perimeter = 2 × (L + W)
  • Unit Conversion: 1 m² ≈ 10.7639 sq ft | 1 sq ft ≈ 0.092903 m²

Verified Worked Examples

Example 1: Standard Bedroom (Rectangle)

A standard master bedroom measuring 15 feet in length by 12 feet in width.

Floor Area:180 sq ft (16.72 m²)
Perimeter:54 ft (16.46 m)

Area = 15 ft × 12 ft = 180 sq ft. Perimeter = 2 × (15 ft + 12 ft) = 54 linear ft of baseboard trim.

Example 2: L-Shaped Living Space

An open living room with a bounding footprint of 20 ft by 16 ft minus an 8 ft by 6 ft corner cutout.

Net Floor Area:272 sq ft (25.27 m²)
Perimeter:72 ft (21.95 m)

Area = (20 × 16) - (8 × 6) = 320 - 48 = 272 sq ft. Rectilinear corner cutout preserves boundary perimeter: 2 × (20 + 16) = 72 ft.

Frequently Asked Questions

How do you calculate the square footage of an L-shaped room?

Multiply the overall bounding length by the overall width, then subtract the area of the missing corner cutout. The boundary perimeter remains 2 × (Overall Length + Overall Width).

How do you convert square feet to square meters?

1 square meter equals approximately 10.7639 square feet. To convert square feet to square meters, multiply by 0.09290304 (NIST SP 811).

Related Home & DIY Tools