How do I calculate square footage?

For a rectangle, multiply the length by the width. For example, a room that is 12 feet long and 10 feet wide is 120 square feet (12 x 10 = 120). For irregular shapes, break the area into rectangles, calculate each one, and add them together.

How many square feet is a 12x12 room?

A 12x12 room is 144 square feet (12 x 12 = 144). This is equivalent to approximately 13.4 square meters or 16 square yards.

How do I convert square feet to square meters?

Divide the square footage by 10.764 to get square meters. For example, 200 square feet divided by 10.764 equals approximately 18.58 square meters. Alternatively, multiply square feet by 0.0929 for the same result.

How much does flooring cost per square foot?

Flooring costs vary widely by material. Vinyl plank costs $2 to $5 per square foot installed, laminate $3 to $8, engineered hardwood $6 to $15, solid hardwood $8 to $20, and natural stone $10 to $30. Labor typically adds $2 to $8 per square foot depending on the material complexity.

What is the difference between square feet and linear feet?

Square feet measures area (length x width) and is used for flooring, painting, and roofing. Linear feet measures only length in one direction and is used for fencing, baseboards, and crown molding. A 10-foot by 12-foot room is 120 square feet in area but 44 linear feet around its perimeter.

Square Footage Calculator

Calculate the area of any room or space in square feet, square meters, and square yards. Supports rectangles, triangles, circles, and L-shaped rooms. Includes a cost estimator.

Shape & Dimensions

Shape

Length (ft)

Width (ft)

Cost Estimator

Price per sq ft ($)Material or project cost per square foot

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Complete Guide to Calculating Square Footage

Square footage is the most common unit of area measurement in the United States and is essential for nearly every construction, renovation, and real estate transaction. Whether you are estimating materials for a flooring project, pricing out a paint job, comparing rental or purchase costs, or verifying the listed size of a property, knowing how to accurately calculate square footage is a fundamental skill. This guide explains how to measure and calculate the area of any space, from simple rectangular rooms to complex multi-section floor plans.

How to Measure Square Footage by Shape

Rectangles and Squares

The simplest and most common calculation. Measure the length and width of the space in feet, then multiply them together. A room that is 15 feet long and 12 feet wide equals 180 square feet (15 x 12 = 180). For a perfect square, simply square the side length. A 10x10 room is 100 square feet. Always measure to the nearest inch for accuracy, and convert inches to decimal feet (6 inches = 0.5 feet) before multiplying.

Triangles

For triangular areas like gable walls, bay window alcoves, or pointed garden beds, multiply the base by the height and divide by two. A triangle with a 10-foot base and 8-foot height has an area of 40 square feet (10 x 8 / 2 = 40). The height must be measured perpendicular to the base, not along the sloped side.

Circles

For circular areas like round patios, pools, or planters, use the formula: Area = pi x radius x radius (pi x r squared). A circle with a radius of 6 feet has an area of approximately 113.1 square feet (3.14159 x 6 x 6 = 113.1). If you know the diameter, divide it by 2 to get the radius.

L-Shaped and Irregular Rooms

For L-shaped rooms and other irregular shapes, divide the space into simple rectangles, calculate the area of each one, and add them together. An L-shaped living room can be split into two rectangles. If one section is 12x10 (120 sq ft) and the other is 8x6 (48 sq ft), the total is 168 square feet. This same approach works for T-shapes, U-shapes, and any other complex floor plan.

Square Footage Conversion Table

From	To	Multiply By	Example
Square Feet	Square Meters	0.0929	200 sq ft = 18.58 sq m
Square Feet	Square Yards	0.1111	200 sq ft = 22.22 sq yd
Square Feet	Acres	0.0000229568	43,560 sq ft = 1 acre
Square Meters	Square Feet	10.7639	20 sq m = 215.28 sq ft
Square Yards	Square Feet	9	25 sq yd = 225 sq ft

Common Room Sizes in Square Feet

Understanding typical room dimensions helps you estimate materials and costs quickly, even before measuring. According to the National Association of Home Builders (NAHB), here are average room sizes in new American homes:

Room Type	Average Size	Typical Dimensions
Master Bedroom	309 sq ft	14 x 22 ft
Secondary Bedroom	131 sq ft	11 x 12 ft
Living Room	330 sq ft	15 x 22 ft
Kitchen	306 sq ft	14 x 22 ft
Bathroom (Full)	50 sq ft	5 x 10 ft
Bathroom (Master)	160 sq ft	10 x 16 ft
Dining Room	156 sq ft	12 x 13 ft
Home Office	132 sq ft	11 x 12 ft
Garage (2-car)	440 sq ft	20 x 22 ft
Laundry Room	68 sq ft	6 x 11 ft

Source: NAHB, American Housing Survey 2023

Cost per Square Foot by Project Type

Once you know the square footage, you can estimate project costs by multiplying the area by the cost per square foot for your specific material or project type. Here are typical cost ranges for common home improvement projects:

Project	Cost per Sq Ft	200 sq ft Cost
Interior Paint (2 coats)	$1.50 - $3.50	$300 - $700
Vinyl Plank Flooring	$2 - $5	$400 - $1,000
Laminate Flooring	$3 - $8	$600 - $1,600
Hardwood Flooring	$8 - $20	$1,600 - $4,000
Ceramic Tile	$5 - $15	$1,000 - $3,000
Carpet (installed)	$3 - $11	$600 - $2,200
Concrete Patio	$6 - $15	$1,200 - $3,000
Deck (composite)	$15 - $30	$3,000 - $6,000
Drywall (installed)	$1.50 - $3	$300 - $600

Tips for Accurate Square Footage Measurements

Use a Laser Distance Measurer

A laser measure (around $30 to $50) is significantly more accurate and faster than a tape measure for room dimensions. It eliminates the need for a helper to hold the other end and can measure up to 100+ feet with accuracy within 1/16 inch. Professional contractors and appraisers consider laser measures the standard tool for area measurements.

Measure at Floor Level

Always measure at floor level for flooring projects and at wall level for painting projects. Walls are not always perfectly straight or plumb, so measuring at the wrong height can give you incorrect dimensions. For flooring, measure into closets and around obstacles that the flooring will need to cover.

Add Waste Factor

Always add a waste factor to your material estimates. For flooring, add 10% for straightforward rectangular rooms and 15% or more for diagonal installations or rooms with many cuts. For paint, round up to the nearest gallon. This prevents costly return trips to the store and potential color matching issues. Use our flooring calculator to factor in waste automatically.

Home Size Statistics 2026

2,430

average square footage of new single-family homes completed in 2024 in the United States, down from the 2015 peak of 2,689 sq ft (U.S. Census Bureau, 2024)

$167

median price per square foot for existing home sales nationally — ranging from $110 in the Midwest to $260+ in coastal markets (NAR, 2024)

10–15%

recommended waste factor when ordering materials — complex layouts, diagonal patterns, and first-time installers should use 15% or more (HomeAdvisor, 2024)

Accurate square footage measurement is the foundation of every successful construction and renovation project, and underestimating material quantities is the number one cause of project delays according to contractor surveys (HomeAdvisor, 2024). By calculating your exact area before purchasing materials, you avoid costly return trips, reduce waste, and ensure consistent material lots for uniform appearance. For complete project planning, pair this calculator with our flooring calculator for material estimates, our paint calculator for wall coverage, or our tile calculator for precise tile counts.