Enter the value to convert into the box and modify the accuracy of the conversion by selecting number of significant figures or decimal places by clicking on the boxes provided.

Conversion Formulae

The conversion formula for hectares (ha) to acres (ac) conversions is as follows:

- 1 hectare = 2.47105381 acres

The conversion formula for acres (ac) to hectares (ha) conversions is as follows:

- 1 acre = 0.40468564224 hectares

Hectares
### Unit System

### Definition

### Base Unit

### Abbreviation

### Information

### More Information

### Global Adoption

### Conversion Formulae

The hectare is a non SI metric unit of 10,000 square metres that is accepted for use with SI units by the BIPM.

SI Metric

The hectare is a non SI accepted unit (See table 6 of the SI Brochure) of area equal to ten thousand square metres.

Metre

Formal: ha

The hectare has its roots in the original metric system of 1795, where the "are" was defined as 100 square metres. The hectare is thus 100 ares i.e. 10,000 square metres. The hectare was adopted by the CIPM (International Committee for Weights and Measures from the French Comité international des poids et mesures) in 1879.

The BIPM has accepted the hectare for use with the SI metric system, although it is not part of theSI metric system and has stated that it expects the use of the hectare to carry on indefinitely.

The hectare is mainly used for expressing the size of areas of land, especially farm land. As it is of a similar magnitude to the acre it has replaced the acre in some countries where Imperial measurements have been replaced by metric units.

Non SI accepted units - Table 6

The hectare is in worldwide use in science and is in general use everywhere except the United States, Liberia and dependent territories. In other English speaking countries, that formerly used Imperial measures, the use of hectare is not universal with the acre still in common use.

- 1 hectare = 100,000,000 square centimetres
- 1 hectare = 1,000,000 square decimetres
- 1 hectare = 100 square decametres
- 1 hectare = 1 square hectometre
- 1 hectare = 10,000 square metres
- 1 hectare = 0.01 square kilometres

- 1 square centimetre = 0.00000001 hectares
- 1 square decimetre = 0.000001 hectares
- 1 square metre = 0.0001 hectares
- 1 square decametre = 0.01 hectares/li>
- 1 square hectometre = 1 hectare
- 1 square kilometre = 100 hectares

Acres
### Unit System

### Definition

### Base Unit

### Abbreviation

### Information

### More Information

### Global Adoption

### Conversion Formulae

The acre is a unit of area, usually used for land, having size of a chain (22 yards) by a furlong (220 yards), thus the acre is 4,840 square yards.

Imperial & US Customary

The acre is defined as the area covered by a rectangle of size one chain by one furlong.

Yard

Formal: ac

The word acre is short so is rarely abbreviated.

Like many Imperial units the acre originates in medieval England. It was originally defined as the area that could be ploughed by a yoke (pair) of oxen in a day. This was formalised as an area of 4 perches by 40 perches, with the perch being a length of 5½ yards. Thus the acre is 22 yards by 220 yards or 1 chain by 1 furlong.

The acre was enacted in the statutes of England prior to 1587, when it was included in 'The Whole Volume of Statutes at Large, which at Anie Time Heeretofore Have Beene Extant in Print'. This definition has remained inuse tothe present day, with only minor changes dueto redefinition of the yard.

Acres are in formal use in the United States, Liberia and dependent territories. It is in common use in many English speaking countries that formerly used Imperial measurements, particularly in the UK for farmland sales.

- 1 acre = 6,272,640 square inches
- 1 acre = 43,560 square feet
- 1 acre = 4,840 square yards
- 1 acre = 0.0015625 square miles

Conversions accurate to 9 decimal places.

- 1 sqaure inch = 0.000000159 acres
- 1 sqaure foot = 0.000022957 acres
- 1 square yard = 0.000206612 acres
- 1 square mile = 640 acres

Conversions accurate to 9 decimal places.

Common Conversions ha to ac

ha | ac |

1 | 2.47 |

2 | 4.94 |

3 | 7.41 |

4 | 9.88 |

5 | 12.36 |

6 | 14.83 |

7 | 17.30 |

8 | 19.77 |

9 | 22.24 |

10 | 24.71 |

ha | ac |

10 | 24.71 |

20 | 49.42 |

30 | 74.13 |

40 | 98.84 |

50 | 123.55 |

60 | 148.26 |

70 | 172.97 |

80 | 197.68 |

90 | 222.39 |

100 | 247.11 |

ha | ac |

100 | 247.11 |

200 | 494.21 |

300 | 741.32 |

400 | 988.42 |

500 | 1,235.53 |

600 | 1,482.63 |

700 | 1,729.74 |

800 | 1,976.84 |

900 | 2,223.95 |

1,000 | 2,471.05 |

Common Conversions ac to ha

ac | ha |

1 | 0.40 |

2 | 0.81 |

3 | 1.21 |

4 | 1.62 |

5 | 2.02 |

6 | 2.43 |

7 | 2.83 |

8 | 3.24 |

9 | 3.64 |

10 | 4.05 |

ac | ha |

10 | 4.05 |

20 | 8.09 |

30 | 12.14 |

40 | 16.19 |

50 | 20.23 |

60 | 24.28 |

70 | 28.33 |

80 | 32.37 |

90 | 36.42 |

100 | 40.47 |

ac | ha |

100 | 40.47 |

200 | 80.94 |

300 | 121.41 |

400 | 161.87 |

500 | 202.34 |

600 | 242.81 |

700 | 283.28 |

800 | 323.75 |

900 | 364.22 |

1,000 | 404.69 |