Square Footage Calculator

Helpful during a home renovation: I needed to compare square footage before remodeling. The square footage calculator made it easy to calculate exact areas for multiple rooms. For irregular layouts like L-shapes and extensions, I leaned on the area calculator, which handles triangles, rectangles, and even ellipses.

This square footage calculator estimates the area of surfaces modeled as geometric shapes such as L-shaped rooms, U-shaped layouts, semicircles, corridors, and composite floor plans. Formulas are provided below.

L-Shaped Room
To calculate the area of an L-shaped room, divide it into two rectangles and use A = l₁ × w₁ + l₂ × w₂. Lengths and widths are measured separately for each rectangle. For example, with parts sized 10 × 8 ft and 6 × 4 ft, the square footage calculator gives A = 80 + 24 = 104 ft².

U-Shaped Layout
For U-shaped layouts, split the shape into three rectangles and sum their areas using A = Σ(length × width). Each segment is treated independently. If sections measure 8 × 4 ft, 6 × 2 ft, and 8 × 4 ft, then A = 32 + 12 + 32 = 76 ft² using the calculator.

Semicircle
The area of a semicircle is A = (½) × π × r², where r is the radius. This covers half of a full circle’s surface. For a semicircular patio with radius 6 ft, the calculator computes A = ½ × π × 6² = ½ × π × 36 ≈ 56.55 ft².

Corridor
Corridors are rectangular, and their area is found with A = length × width. This applies to hallways or linear spaces. A 20 ft long corridor that’s 3 ft wide results in A = 20 × 3 = 60 ft² using the square footage calculator.

Composite Room
For irregular rooms, divide the space into known shapes and total their areas. Use A = A₁ + A₂ + A₃… as needed. A room split into a 10 × 10 square and a 5 × 6 rectangle gives A = 100 + 30 = 130 ft² with the calculator.