Square Footage Calculator

A square foot is the area of a square measuring one foot along each edge. For a rectangle, area = length × width, with both measurements expressed in feet. A 12-foot by 15-foot floor covers 180 square feet.

Length and width are linear measurements; multiplying them gives area. You cannot convert 10 linear feet directly into square feet. A strip 10 feet long and 2 feet wide covers 20 square feet, while a strip of the same length and 3 feet wide covers 30 square feet.

For smaller measurements, first convert inches to feet by dividing by 12, or calculate square inches and then divide by 144. Both methods give the same area.

Measure a rectangular room from edge to edge along two perpendicular sides. Keep the tape level, record the unit next to each measurement, and check the dimensions before ordering materials. Use actual measurements rather than a room’s advertised size.

If the room contains a recess or alcove, measure it as a separate section. Only include a closet or attached space if it belongs in the area you intend to cover. A room area calculation estimates geometry; it does not determine which spaces count toward a property’s advertised living area.

How to calculate wall square footage

Use wall width as one dimension and wall height as the other. For a 15-foot-wide wall that is 8 feet high, gross area is 120 sq ft. Subtract separately measured openings if your project requires net coverage. The calculator does not automatically deduct windows, doors or other openings.

Select Feet + inches to enter each dimension in two fields. Keep the inches component below 12; carry any whole feet into the feet field. Six inches equals 0.5 feet, so 12 feet 6 inches is 12 + 6 ÷ 12 = 12.5 feet.

A room measuring 12 ft 6 in by 10 ft 3 in has area 12.5 × 10.25 = 128.125 sq ft. Do not enter 12.6 feet to represent 12 feet 6 inches: decimal feet use tenths of a foot, rather than inches.

Switching a room’s unit preserves the physical dimensions. The new field display may be rounded for readability; the calculation keeps the underlying measurement until you edit a dimension.

Calculate each room first, then add the individual areas. A 12 × 15 ft living room is 180 sq ft and a 10 × 10 ft bedroom is 100 sq ft, giving 280 sq ft in total. Name your rooms to make the breakdown easier to check.

Each room can use a different unit. For example, a 3 × 4 meter room covers 12 m², approximately 129.167 sq ft, and can be added to rooms measured in feet without manually converting their dimensions.

Add room creates a blank measurement card. Duplicate copies a room’s current measurements for repeated layouts; remove any copy that represents the same physical space. Shared floor areas must appear only once. Dimensions alone cannot tell the tool that two entries overlap.

Draw a simple floor plan and divide it into shapes with boundaries that meet but do not overlap. In an L-shaped room, one rectangle might measure 12 × 10 ft and the other 5 × 4 ft. The sections cover 120 and 20 sq ft, for a combined 140 sq ft.

Measure the second section from the shared boundary, rather than measuring the full length of both arms. Counting the corner in both rectangles overstates the total. The L-shaped Room diagram shows one way to place the boundary.

For more complex outlines, use Multiple Rooms to add rectangular or triangular sections. This is a section-summing tool: it does not infer a polygon, calculate overlapping regions, or subtract cutouts automatically.

Multiply square feet by 0.09290304 to get square meters. Thus 180 sq ft equals 16.7225472 m², approximately 16.72 m². To convert square meters to square feet, divide by 0.09290304.

• 1 square foot = 144 square inches.
• 1 square yard = 9 square feet.
• 1 acre = 43,560 square feet.
• 1 square meter ≈ 10.7639104 square feet.

Area conversions square the corresponding length factor. Dividing square inches by 12 is incorrect because both length and width contribute an inch-to-foot conversion.

Keep measured floor area separate from the purchase allowance. For a 280 sq ft floor and 5% waste, the extra allowance is 14 sq ft and the material purchase estimate is 280 × 1.05 = 294 sq ft. The floor itself still measures 280 sq ft.

Multiply purchase area by a price in the matching unit. At an illustrative price of $3 per square foot, 294 sq ft costs $882 in materials. This is a calculation example, not a current market quote. If your price is per square meter, the tool converts purchase area to m² before multiplying.

Choose an allowance that suits your layout and product instructions. Cutting patterns, offcuts, repairs and pack sizes can affect the actual order; this tool does not round flooring purchases to whole boxes. Currency selection changes formatting and does not convert your quote between currencies.

Planning a driveway or landscaping project? Use our Gravel Calculator to estimate material volume and weight. Our Percentage Calculator can also help check an allowance.