Square Footage Calculator

About Square Footage Calculator

This square footage calculator measures the area of any room or space. Enter dimensions for rectangular, circular, triangular, or L-shaped areas and get instant results in square feet, square metres, and square yards. Add multiple rooms for a combined total, with each room using a different shape if needed.

Area Formulas by Shape

Shape	Formula	Example
Rectangle / square	Length x Width	12 ft x 10 ft = 120 sq ft
Circle	pi x r²	Radius 5 ft: 3.14159 x 25 = 78.54 sq ft
Triangle	(Base x Height) / 2	8 ft base x 6 ft height: 48 / 2 = 24 sq ft
L-shape	(L1 x W1) + (L2 x W2)	Split into two rectangles and add their areas

Area Unit Conversions

From	To	Multiply By
1 square foot	Square metres	0.0929
1 square metre	Square feet	10.764
1 square foot	Square yards	0.1111 (1/9)
1 square yard	Square feet	9
1 acre	Square feet	43,560
1 hectare	Square metres	10,000

Typical Room Sizes

Use these as sanity checks when measuring. If your calculation is way outside these ranges, double-check your measurements:

Room	Typical Size Range	Square Footage
Small bedroom	9 x 10 to 10 x 12	90-120 sq ft
Standard bedroom	11 x 12 to 12 x 14	132-168 sq ft
Master bedroom	14 x 16 to 16 x 20	224-320 sq ft
Living room	12 x 16 to 16 x 20	192-320 sq ft
Kitchen	10 x 12 to 14 x 16	120-224 sq ft
Bathroom	5 x 8 to 8 x 10	40-80 sq ft
Garage (single car)	12 x 20	~240 sq ft
Garage (double car)	20 x 22	~440 sq ft
Studio apartment	-	300-600 sq ft total
Average UK house	-	~818 sq ft (76 sq m)
Average US house	-	~2,300 sq ft (214 sq m)

How to Measure Rooms

Step	Instructions
1. Use a tape measure	Measure along the floor at the base of the walls - this is the most accurate point
2. Measure length and width	Measure the longest and widest walls of each section
3. Record in feet and inches	Example: 12 ft 6 in = 12.5 feet. Convert inches by dividing by 12
4. Handle irregular shapes	Split into rectangles, triangles, or circles and add the areas
5. Subtract obstacles if needed	Columns, built-in cabinets, or permanent fixtures that reduce usable area

Common Uses for Square Footage

Purpose	What You Need Area For	Related Tool
Paint estimate	Wall area determines gallons needed	Paint calculator
Flooring purchase	Floor area determines tile, hardwood, or carpet quantity	Tile calculator
HVAC sizing	Room area determines BTU requirements	BTU calculator
Concrete slab	Area x depth = volume needed	Concrete calculator
Mulch / gravel	Area x depth = cubic yards to order	Mulch calculator
Real estate listing	Total living area for property listing	-
Carpet purchase	Area in square yards (divide sq ft by 9)	-
Rental pricing	Price per square foot comparison	-

Handling Irregular Rooms

Most real rooms are not perfect rectangles. Here is how to measure common irregular shapes:

Room Shape	How to Measure
L-shaped room	Split into two rectangles, measure each, and add areas together
Room with a bay window	Measure the main rectangle plus the bay window area (triangle or trapezoid)
Room with a closet alcove	Measure the main room and the closet separately, add if needed
Round / curved wall	Approximate with a rectangle and add or subtract the curved portion
Open plan (multiple areas)	Break into separate rectangular zones and add them all

Price Per Square Foot

Square footage is the standard unit for comparing property prices, renovation costs, and flooring prices. To find price per square foot, divide the total cost by the total square footage. For example, a $300,000 home with 2,000 sq ft costs $150 per square foot.

For volume calculations (concrete, gravel, mulch), the cubic yards calculator takes area measurements and adds depth. All calculations run in your browser with no data stored.