Square Feet Calculator
Calculate the square footage area of rooms, walls, land, circles, and triangles. Convert to square meters, square yards, and acres with material pricing.
| Square Yards (yd²) | 27.38 Sq Yds |
| Square Meters (m²) | 22.89 m² |
| Square Inches (in²) | 35,481.6 Sq In |
| Acres Equivalent | 0.00565 Acres |
What is Square Footage (sq ft / ft²)?
Square footage is a standard imperial measurement of two-dimensional surface area. One square foot represents the surface of a flat square with sides measuring exactly 1 foot (12 inches) on each side, totaling 144 square inches.
Square footage is the universal standard metric used for home real estate listings, flooring orders (hardwood, vinyl plank, tile, carpet), wall painting projects, lawn sodding, and roofing estimates.
The Mathematics of 2D Area Calculations
Here are the standard geometric formulas used to calculate square footage across different surface shapes:
When measured in inches: Area (sq ft) = (Length in * Width in) / 144
Circle: Area (sq ft) = π * (Radius in ft)^2
Triangle: Area (sq ft) = 0.5 * Base (ft) * Height (ft)
Trapezoid: Area (sq ft) = ((Base 1 + Base 2) / 2) * Height (ft)
Total Material Needed = Net Area * (1 + Waste % / 100)
Total Project Cost ($) = Total Material Needed * Price per Square Foot ($/sq ft)
Step-by-Step Worked Example
Suppose you are installing hardwood flooring in a 14-foot by 16-foot master bedroom with 10% waste buffer at $4.50 per square foot:
- Calculate net room square footage:
14 ft * 16 ft = 224.0 sq ft. - Add 10% cutting and defect waste buffer:
224.0 * 1.10 = 246.4 sq ft to order. - Calculate total material cost:
246.4 sq ft * $4.50 = $1,108.80. - Convert to square yards (for carpet):
246.4 / 9 = 27.38 sq yds. - Convert to square meters:
246.4 * 0.092903 = 22.89 m².
Master Square Footage Area Conversion Table
Direct equivalents from square feet to other area measurement units:
| Square Feet (ft²) | Square Yards (yd²) | Square Meters (m²) | Square Inches (in²) | Acres (ac) |
|---|---|---|---|---|
| 1 ft² | 0.111 yd² | 0.093 m² | 144 in² | 0.000023 ac |
| 9 ft² (1 Sq Yd) | 1.000 yd² | 0.836 m² | 1,296 in² | 0.000207 ac |
| 100 ft² (1 Roofing Square) | 11.11 yd² | 9.290 m² | 14,400 in² | 0.002296 ac |
| 500 ft² | 55.56 yd² | 46.452 m² | 72,000 in² | 0.011478 ac |
| 1,000 ft² | 111.11 yd² | 92.903 m² | 144,000 in² | 0.022957 ac |
| 2,000 ft² | 222.22 yd² | 185.806 m² | 288,000 in² | 0.045914 ac |
| 43,560 ft² (1 Acre) | 4,840 yd² | 4,046.86 m² | 6,272,640 in² | 1.000000 ac |
How to Measure L-Shaped & Irregular Floor Plans
Real-world homes rarely consist of simple rectangles. To find the square footage of complex L-shaped, T-shaped, or angled rooms:
- Decompose into Simple Rectangles: Divide the irregular floor plan into smaller rectangular sections (e.g. Section A and Section B).
- Measure Each Section Separately: Find the length and width of Section A, then Section B.
- Add the Sections Together: Sum the individual square footages:
Total Area = Area A + Area B. - Subtract Unusable Cutouts: If a room contains an island, fireplace hearth, or stairwell, calculate its area and subtract it from the total.
5 Tips When Buying Flooring and Tile
Frequently Asked Questions
For rectangular rooms or surfaces, measure the length and width in feet and multiply them together. Formula: Square Feet = Length (ft) * Width (ft).
Divide the total square inches by 144 (since 12 inches * 12 inches = 144 square inches in 1 sq ft). For example, 1,440 sq inches equals 10 sq ft.
In roofing and siding construction, one "square" is an industry term that represents exactly 100 square feet of roof surface area (approx 3 bundles of asphalt shingles).
Measure the perimeter of the room (sum of all wall lengths) and multiply by ceiling height. Then subtract the square footage of doors (approx 21 sq ft each) and windows (approx 15 sq ft each).
A 10-foot by 10-foot room equals exactly 100 square feet.