Area Converter

How do you convert area units?

To convert any area, change the value into square meters, then divide by the size of the target unit in square meters. Each unit here has an exact size in square meters, so one multiplication and one division always give the answer.

The two-step method

1. Multiply the value by the size of the starting unit in square meters.
2. Divide the result by the size of the target unit in square meters.

For example, a room measuring 12 ft by 15 ft has an area of 180 square feet. Converting to metric: 180 × 0.09290304 = 16.72 m². Going the other way, a 4 m by 5 m room is 20 m², and 20 ÷ 0.09290304 = 215.28 ft². The square feet to square meters converter and the square meters to square feet converter handle any floor plan.

Why area factors are squared

Area is length times length, so an area factor is the square of the matching length factor. A foot is 0.3048 m, so a square foot is 0.3048 × 0.3048 = 0.09290304 m². A yard is 3 feet, so a square yard is 3 × 3 = 9 square feet, not 3. The same rule catches people with metric units: 1 m is 100 cm, but 1 m² is 100 × 100 = 10,000 cm². If you have lengths rather than an area, multiply them first in the same unit, or convert each side with the length converter before multiplying.

What is the difference between an acre and a hectare?

A hectare is about 2.47 times as large as an acre: a hectare is 10,000 m², while an acre is 43,560 ft², or about 4,046.86 m².

The acre is an old English unit, traditionally the land a team of oxen could plow in a day. Its modern definition is a strip one furlong (660 ft) long and one chain (66 ft) wide, which gives exactly 43,560 square feet, or 4,840 square yards. An acre has no fixed shape; it is simply that much area. For a sense of scale, an American football field of 360 ft by 160 ft, including the end zones, covers about 1.32 acres.

The hectare is the metric land unit: a square 100 m on each side, or 10,000 m². It is about 2.47 acres, so land measured in hectares always shows a smaller number than the same land in acres. One square kilometer is 100 hectares, and one square mile is 640 acres, about 259 hectares. The acres to hectares converter is useful when comparing farm listings between countries.

Survey acres and the US survey foot

Older US land records may use the US survey foot, which is about 2 parts per million longer than the international foot. The difference makes a survey acre roughly 4,046.87 m² instead of 4,046.86 m². The US survey foot was officially retired at the end of 2022, and new work uses the international foot, as this converter does.

How do metric and US area units relate to each other?

Every US customary area unit is the square of an exact length, so each one has an exact size in square meters: a square foot is 0.3048 × 0.3048 = 0.09290304 m², and an acre is exactly 4,046.8564224 m². The table below lists the relationships that the converter on this page is built on.

The square meter is the SI unit of area. It is derived from the meter, which the BIPM SI Brochure defines by fixing the speed of light in vacuum at exactly 299,792,458 m/s. The hectare is not an SI unit, but the SI Brochure accepts it for use with the SI because it is so widely used for land. On the US side, the 1959 International Yard and Pound Agreement fixed the yard at 0.9144 m, and NIST Handbook 44 defines the acre as 43,560 ft² and the square mile as 640 acres. Area adds a second dimension to length, and volume adds a third; the volume converter covers cubic units.

Which area units are used where?

Square meters and hectares are the standard almost everywhere, while square feet, acres and square miles dominate in the United States, and the UK still quotes many homes in square feet and farms in acres.

• Square meters: floor area of homes, offices and rooms in most of the world, plus building plans and flooring.
• Square feet: real estate listings, rent and flooring in the US and Canada, and commercial property in the UK and India.
• Square yards: carpet, turf and fabric sold by area, mainly in the US.
• Acres: farmland, residential lots and parks in the US, UK, Canada and Australia.
• Hectares: agriculture, forestry, land registries and planning in most countries outside the US.
• Square kilometers and square miles: the size of cities, countries, lakes and wildfires; pick square miles or square kilometers in the converter at the top of this page.
• Square inches and square centimeters: screen and paper sizes, circuit boards and small parts.

For material estimates such as paint, tiles or concrete that start from an area, the construction calculators take it from there.

How do you measure the area of an irregular room or plot?

Split the shape into rectangles, triangles and circles, work out each area in the same unit, then add them together. Measuring every piece in feet (or every piece in meters) before you multiply avoids mixing units, which is the most common source of error.

• Rectangle: length × width.
• Triangle: ½ × base × height, where the height is measured at a right angle to the base.
• Circle: π × radius², where the radius is half the diameter.
• Trapezoid: ½ × (the two parallel sides added together) × the distance between them.

Worked example: an L-shaped living room splits into a 12 × 15 ft rectangle and a 6 × 8 ft alcove, so its area is 180 + 48 = 228 ft², or 21.18 m². A triangular garden bed with a 10 ft base and a 6 ft height adds 30 ft², and a round patio 10 ft across (5 ft radius) covers π × 5² ≈ 78.54 ft², about 7.3 m². The square feet to square meters converter turns the total into metric, and the feet to meters converter helps if you would rather convert each side first.

Land parcels are rarely neat shapes. Surveyors record each corner as a coordinate and calculate the enclosed area with the surveyor’s (shoelace) formula, which is what mapping and GIS software does behind the scenes. For flooring, tile or turf, measure the finished area this way, then add a waste allowance before ordering.