acre (ac)

1 acre = 4,046.8564224 square metres

What is acre?

An acre is a unit of area in imperial and US customary systems equal to 43,560 square feet. It is the standard unit for measuring agricultural land, property lots, and parks in the United States and United Kingdom.

Notes: Land area unit

Real-world uses

Acres are used for land parcels, farm sizes, and real estate in the US, UK, and some Commonwealth countries. Zoning laws often specify minimum lot sizes in acres. An American football field (including end zones) is about 1.32 acres.

History

The acre originated in medieval England as the amount of land a yoke of oxen could plough in one day. The word comes from Old English "æcer." It was standardized as a strip 1 furlong (660 ft) by 1 chain (66 ft), yielding 43,560 square feet.

Common mistakes

Assuming an acre is a square measure with specific dimensions—it is 43,560 sq ft but can be any shape. Also, confusing acres with hectares: 1 acre ≈ 0.405 hectares, so roughly 2.5 acres make one hectare.

When is this conversion used?

Converting between acre and square metre is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region.

How to convert acre to square metre

To convert acre to square metre, multiply the value by 4,046.8564224.

Conversion formula (from base unit)

x * 4046.8564224

Measurement standards

The square metre is the SI derived unit of area. The hectare (10,000 m²) is accepted for use with the SI by the BIPM, particularly for land measurement, though it is not an SI unit itself.

Did you know?

Vatican City, the world's smallest independent state, covers just 0.44 km² (about 109 acres) — smaller than many golf courses. By contrast, Russia spans over 17.1 million km², nearly 39 million times larger.

Quick reference: acre to square metre
acressquare metres
0.1404.68564224
0.52,023.4282112
14,046.8564224
28,093.7128448
520,234.282112
1040,468.564224
25101,171.41056
50202,342.82112
100404,685.64224
2501,011,714.1056
5002,023,428.2112
1,0004,046,856.4224

Common values

Common values
acressquare metres
A4 paper0.00001532 acres0.062 square metres
Parking space0.00308882 acres12.5 square metres
Tennis court0.06446238 acres260.87 square metres
Football field (soccer)1.76433242 acres7,140 square metres
Central Park, NYC842.6293508 acres3,410,000 square metres

Full acre conversion table

Full acre conversion table
Unit Value Factor
square metre1 ac = 4,046.8564224 m²× 4,046.8564224
square kilometre1 ac = 0.00404686 km²× 0.00404686
square foot1 ac = 43,560 ft²× 43,560
square mile1 ac = 0.0015625 mi²× 0.0015625
hectare1 ac = 0.40468564 ha× 0.40468564
square centimetre1 ac = 40,468,564.224 cm²× 40,468,564.224
square inch1 ac = 6,272,640 in²× 6,272,640
square yard1 ac = 4,840 yd²× 4,840
are1 ac = 40.46856422 a× 40.46856422