Room & Measurement

Square Footage Calculator

Calculate square footage and area for complex spaces using rectangles, triangles, circles, and cutout deductions.

Geometric Sections

Combine multiple shapes and subtract openings

rectangle

Length (ft)

Width (ft)

triangle

Base (ft)

Height (ft)

deduction

Length (ft)

Width (ft)

Total Net Area

Multi-unit conversion outputs

Net Combined Area

281 sq ft

26.11 m² (31.22 sq yards)

Square Feet

281

Square Meters

26.11

Square Yards

31.22

Geometric Breakdown:

+ Main Living Room:300 sq ft

+ Bay Window Nook:16 sq ft

− Stair Opening Cutout:35 sq ft

Total net area is 281 sq ft (26.1 m² / 31.2 sq yd) calculated across 3 geometric segments.

How It Works & Calculation Formula

Formula Summary: Total Area = Σ(Rectangles + Triangles + Circles) − Deductions. Accurate geometric unit conversions.

Step-by-Step Calculation:

Rectangle: Length × Width.
Triangle: (Base × Height) ÷ 2.
Circle: π × Radius².
Deductions (staircases, fireplaces, interior columns): Subtracted from total.
Instant conversion to Square Feet, Square Meters, Square Yards, and Acres.

Worked Example Calculation

Sample Inputs:

Main Living (Rect):20 ft × 15 ft
Bay Window (Tri):8 ft base × 4 ft height
Stairwell Deduction:10 ft × 3.5 ft

Expected Output:

Net Area: 281.0 sq ft (26.1 m² / 31.2 sq yd / 0.0065 acres). Individual breakdown provided for every shape.

Practical Tips & Trade Guidelines

Break complex irregular rooms into simple basic shapes (rectangles, right triangles, and half circles).
In real estate, square footage is measured to the outside surfaces of exterior walls for single-family homes.
Do not include unfinished basements, attics with low sloping ceilings (<7 ft), or open exterior decks in livable square footage.
Verify all dimensions twice before signing construction or material procurement contracts.

Frequently Asked Questions

For a rectangular room, multiply length by width in feet. For example, 10 feet × 12 feet = 120 square feet.

Important Renovation Notice

Calculations are mathematical estimates based on standard trade conventions. Always field-verify room measurements, examine packaging labels, and check with a licensed contractor before purchasing materials or starting installation.