Convert area measures (m², hectare, acre)

As with lengths, everything goes through an SI unit: the square meter. Square inches, square feet, and square yards are the squares of the international length factors (0.0254², 0.3048², 0.9144²). The hectare is 10⁴ m². The international acre is 4,046.8564224 m² (NIST). Land in ares (1 are = 100 m²) converts via m² (100 ares = 1 ha).

A(m²) = x × kfrom ; y = A(m²) / kto

1 ha = 10 000 m²

1 acre = 4 046,8564224 m²

SI area units derive from the meter. The international acre is tied to the international yard; its value in m² is exact in the NIST table. Historical French arpents, perches, and farm “days” are not in the list: their definitions varied by province. To paint a wall, area in m² is computed geometrically (paint tool); this converter only changes unit.

Value

Numeric area, without the unit.

From

mm² through km², plus in², ft², yd², and international acre.

To

Same list. For ares: 1 are = 100 m², in two steps via m².

Assumptions

• Acre = international NIST acre, not an arpent.
• US customary “square” units are squares of international lengths.
• 1 ha = 10,000 m² exactly.

Limits

• No are as a direct option, no arpent, no distinct US survey acre.
• An L-shaped room does not “convert”: you need geometric area first.
• The length converter does not replace this one (12 ft is not 12 ft²).

1 ha = 10,000 m², a square 100 m on a side. 2.5 acres ≈ 1.01 ha: useful for a US or UK listing. For a 50 m² wall to paint, stay in m² and open the paint calculator: changing unit does not give liters.

• Converting a length and calling it m².

  ft → m then, if needed, multiply two lengths. Or type the already computed area here.

• Taking the acre as exactly 4,000 m².

  The international acre is 4,046.8564224 m². 4,000 m² is a shortcut.

• Confusing hectare and are.

  1 ha = 100 ares = 10,000 m². 1 are = 100 m².

• Length converterEvery value goes through the meter, then to the target unit. The inch is 25.4 mm exactly since the 1959 agreement, as in the NIST SI conversion factors.
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• Weight (mass) converterEveryday speech says “weight”; SI speaks of mass. Conversion goes through the kilogram. The pound (lb) is 0.45359237 kg exactly, a NIST factor, not a weighing on Earth.
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Written by Rédaction HexaCalc (editorial team). Content last updated: August 25, 2026. No third-party medical or financial review is claimed.

• NIST Guide to the SI, Appendix B: Conversion Factors — National Institute of Standards and Technology
• The International System of Units (SI) — Bureau international des poids et mesures (BIPM)