About Area Conversion
Area conversions are used in real estate, agriculture, construction, and land surveying.
Area factors are squared
Area is length times length, so area conversion factors are the square of length factors. A foot is 0.3048 m, so a square foot is 0.3048² = 0.09290304 m². An inch is 2.54 cm, so a square inch is exactly 6.4516 cm². Using the length factor by mistake is the most common area error.
Going the other way, one square meter is about 10.764 square feet, and one square centimeter is about 0.155 square inches.
Land area: hectares and acres
A hectare is 10,000 m², a square 100 meters on each side, and a square kilometer is 100 hectares. An acre is 43,560 square feet, exactly 4,046.8564224 m². One hectare is about 2.471 acres, and one acre is about 0.4047 hectares. A square mile is 640 acres.
Many countries also use traditional land units, such as the bigha, marla or tsubo. Their size varies by region, so check the local definition before converting them.
Worked example: floor area
A 1,500 square foot apartment is 1,500 × 0.09290304 = 139.35 m². A 90 m² apartment is 90 × 10.7639 = 968.8 square feet.