Square Footage Calculator

Last Updated:

Calculate room area in square feet or square meters. Instantly converts between sq ft and sq m.

120 sq ft

= 11.1 sq m

📐 Formula

Area = Length × Width. Sq ft to sq m: multiply by 0.092903. Sq m to sq ft: multiply by 10.7639

How to Use the Square Footage Calculator

1

Select room shape

Choose rectangle (most rooms), triangle, circle, or L-shape. Irregular rooms can be broken into multiple simple shapes and added together.

2

Enter dimensions

Input length and width in feet or metres. For an L-shaped room, the calculator requires the outer dimensions and the dimensions of the rectangular section to subtract.

3

Add all rooms

Use the multi-room feature to calculate each room separately and sum to total home square footage. Label each room for reference.

4

Convert units if needed

Toggle between square feet, square metres, and square yards. The calculator converts automatically — useful when comparing US listings (sq ft) to international properties (sq m).

What Counts as Square Footage?

Square footage measurement standards are not uniformly regulated in the United States, which causes significant confusion. The American National Standards Institute (ANSI) provides guidelines (ANSI Z765) used by most appraisers: finished, above-grade living area is what counts for official square footage. This includes bedrooms, living rooms, kitchen, dining room, bathrooms, hallways, and finished bonus rooms — but only if they meet ceiling height requirements (generally 7 feet minimum).

What typically does not count in standard square footage: unfinished basements (even if used regularly), garages, attics (unless finished and accessible by a permanent staircase), covered porches and patios, and crawl spaces. Some listings include these spaces in a "total area" figure separate from living area — always clarify which is quoted. A 2,400 sq ft listing that includes an unfinished basement may have only 1,800 sq ft of actual living space.

Measuring Your Own Rooms Accurately

Use a laser distance measurer (available for $25–$50) for speed and accuracy over a tape measure. Measure each room at its widest points from wall to wall, including any alcoves or bump-outs. For irregular rooms, sketch the room on paper, divide it into rectangles, calculate each rectangle, and sum them. Bay windows typically add to the interior square footage; exterior protrusions like columns do not. Closets are included in room area. Stairways count at the floor level only.

Square Footage and Property Value

Appraisers and real estate agents use price per square foot as a primary valuation benchmark: divide the sale price by the finished square footage to get the rate, then apply it to the subject property. In practice, the rate is not uniform across a home — primary bedrooms and main living areas carry higher value per square foot than storage rooms or utility spaces. Additions and conversions (garage-to-bedroom, basement finishing) increase square footage but may not increase value proportionally if the quality of finish or ceiling height is below grade for the neighbourhood.

Sources & Methodology

Calculations are based on the most current publicly available data from authoritative government and industry sources:

Frequently Asked Questions

Measure the length and width of the room in feet, then multiply the two numbers. For irregular rooms, divide them into rectangles, calculate each area, and add them together.
1 square meter = 10.7639 square feet. 1 square foot = 0.092903 square meters. So a 100 sq ft room is about 9.29 sq m.
1 acre = 43,560 square feet, or approximately 4,047 square meters. A typical suburban house lot is 0.25–0.5 acres (10,890–21,780 sq ft).
Measure each room's length × width in feet. Add all rooms together. For irregular shapes, break into rectangles and add. Include all finished interior areas: bedrooms, living room, kitchen, finished basement. Exclude: unfinished basement, garage, attic (unless finished), covered porches. A measuring tape or laser measure gives the most accurate results.
No. Standard US real estate square footage (GLA — Gross Living Area) excludes garages, unfinished basements, covered patios, and any space that is not heated, finished, and livable. Finished basements are a gray area — some appraisers include them, some list them separately. Always ask how square footage was measured when comparing listings.