Area Converter
Convert an area between square meters, square centimeters, square kilometers, square inches, square feet, square yards, square miles, acres and hectares.
Updated Formula covered by automated tests
Convert floor space, land and map areas between square meters, square centimeters, square kilometers, square inches, square feet, square yards, square miles, acres and hectares. People reach for it when comparing an apartment listed in square meters with one in square feet, ordering flooring or turf sold by the square yard, reading a farm or lot size in acres or hectares, or checking a country’s size in square miles.
The single biggest trap with area is forgetting that the conversion factor is squared. One meter is 3.28 feet, but one square meter is 3.28 × 3.28 = 10.76 square feet, not 3.28. Using the length factor on an area understates a room by more than two thirds, which is an expensive mistake when ordering tiles or carpet.
The formula
- m² per source unit
- Square meters in one unit of what you typed, for example 0.09290304 for a square foot
- m² per target unit
- Square meters in one unit of the result
- ha
- Hectare, a square 100 m on each side, the standard land unit in metric countries
A square unit is a square whose side is one of the length units, so its size is that length multiplied by itself. Because the foot is exactly 0.3048 m, the square foot is exactly 0.09290304 m², and the same squaring gives exact factors for square inches, yards and miles. The converter stores all of these as square meters and divides out to every other unit.
The acre is older than the units around it. It began as the land a team of oxen could plow in a day and was later standardized as a strip one furlong (660 ft) long and one chain (66 ft) wide, which is 43,560 square feet. The hectare was introduced with the metric system as 100 ares, where an are is 10 m by 10 m; one hectare is about 2.47 acres.
Worked example
Sofia is moving from Madrid to Chicago. Her Madrid apartment is listed as 85 m², and the Chicago listings she is browsing quote square feet. She also needs to price carpet sold by the square yard.
- 1 Square the length factor: 0.3048 × 0.3048 = 0.09290304 m² per square foot.
- 2 Divide the area by it: 85 ÷ 0.09290304 = 914.93 ft².
- 3 For square yards, divide by 9 ft² per yd²: 914.93 ÷ 9 = 101.66 yd².
Result: Her 85 m² apartment is about 915 square feet, so Chicago apartments around 900 to 950 ft² are a like-for-like comparison. Carpeting the same floor area would take about 102 square yards before allowing for waste.
Before you rely on the result
- The converter changes units of an area you already know; it does not compute areas of shapes from their dimensions.
- Uses the international acre and foot. Historic survey acres, Scottish or Irish acres, and local units such as the Japanese tsubo are not included.
- Map areas of large regions depend on the projection and survey used, so published figures for the same country can differ slightly.
Frequently asked questions
Do real estate listings measure square footage the same way everywhere?
No, and the conversion cannot fix that. Some markets quote internal floor area, some include wall thickness, balconies or shared hallways, and US listings often follow local or appraisal conventions. Two homes with the same quoted square footage can differ in usable space, so ask how the figure was measured.
How do I find the area of a room before converting?
For a rectangle, multiply length by width in the same unit, for example 4.2 m × 3.5 m = 14.7 m². For an L-shaped room, split it into rectangles and add them. Convert the total afterwards rather than converting each side, which avoids rounding twice.
Is a US acre the same as a UK acre?
Today both use the international acre of 4,046.8564224 m². Older US land records may be based on the US survey foot, which makes a survey acre about 0.016 m² larger, a difference of 4 parts per million that only matters for very large tracts.
How much flooring should I order after converting?
Order more than the converted floor area. Flooring installers commonly add a waste allowance of roughly 5 to 10 percent for straight layouts and more for diagonal or herringbone patterns, but the right figure depends on the material and room shape, so check the manufacturer’s guidance.
Sources
- NIST Handbook 44, Appendix C: General tables of units of measurement (nist.gov)
- NIST: The US survey foot (nist.gov)