Convert it! | Tradional Units | Imperial Units |

Commercial Units | Metric System |

## Traditional English Units

### Hundred

An area equal to 100 hides or 12,000 acres about 18.75 square miles. The hundred was approximately the area of a village with its associated fields, so the name "hundred" came to mean a minor division of a shire or county.

### Hide

The hide, also known as the carucate, was the amount of land that could be cultivated by a single ploughman and thus the amount of land necessary to support a family. In early times the hide varied between 60 acres and 180 acres. The hide was standardized as 120 acres after the Norman conquest of 1066. The hide continued in use throughout medieval times, but it is now obsolete. The unit was

### Bovate

An area equal to 1/8 hide or 15 acres. The word comes from the Latin bovis, an ox, indicating that the bovate was an area that could be farmed with the help of one ox. The bovate was also known as the oxgang

### Acre

In Britain, land is traditionally measured by the acre, a very old Saxon unit. There are references to the acre at least as early as the year 732. The word "acre" also meant "field", and as a unit an acre was originally a field of a size that a farmer could plough in a single day. Most area units were eventually defined to be the area of a square having sides equal to some simple multiple of a distance unit, like the square yard, but the acre was never visualized as a square. An acre is the area of a long and narrow Anglo-Saxon farm field, one furlong (40 rods) in length but only 4 rods wide. This works out to be exactly 4840 square yards.

### Rood

An area of 1 furlong long by 1 rod wide, or 1210 square yards. There are 4 roods to the acre. The unit was also known as the Farthingdale.

### Perch

A perch of area covers exactly 272.25 square feet. There are 40 perches in a rood and 160 perches in an acre.

## Commercial Units

### Square (sq)

A commercial unit of area used for measuring roofing material, finished lumber, and other building materials. One square equals 100 square feet or 11.111 square yards.

### Bolt

A commercial unit of length or area used to measure finished cloth. Generally speaking, one bolt represents a strip of cloth 100 yards long, but the width varies according to the fabric. Cotton bolts are traditionally 42 inches wide and wool bolts are usually 60 inches wide. Thus a bolt of cotton is 116.667 square yards and a bolt of wool is 1660 square yards.

## Imperial Units

### Square Inch (in^{2} or sq in)

A traditional unit of area. 1 in^{2} equals
exactly 6.4516 cm^{2} or 645.16 mm^{2}.

### Square Foot (ft^{2}or sq ft)

A traditional unit of area. 1 ft^{2} equals 144
in^{2} or exactly 929.0304 cm^{2} (0.092 903 04 m^{2}).

### Square Yard (yd^{2} or sq yd)

A traditional unit of area. 1 yd^{2} equals 9 ft^{2},
1296 in^{2}, or exactly 0.83612736 m^{2}.

### Square Rod (rd^{2} or sq rd)

One square rod is equal to 272.25 square feet or 30.25 square yards, or 25.2929 square meters.

### Square Chain (ch^{2} or sq ch)

A traditional unit of area in English surveying,
defined to be the area of a square whose sides equal Gunter's chain (4
rods or 22 yards). Thus the square chain equals 16 square rods, 484 square
yards, 4356 square feet or 1/10^{th} acre.

### Square Mile (mi^{2} or sq mi)

A traditional unit of area. One square mile is equal to 640 acres, 3,097,600 square yards, 259 hectares, or 2.589 square kilometres.

## Metric Units

### Square Centimetre (cm^{2})

The unit of area. 1 cm^{2} equals 1/10,000^{th}
m^{2} or approximately 0.155 square inches.

### Square Metre (m^{2})

The SI unit of area, equal to 10,000 square centimetres or approximately 1.196 square yards.

### Hectare

The customary metric unit of land area, one hectare is a square hectometre, the area of a square 100 metres on each side: approximately 107,639 square feet, 11,960 square yards, or 2.471 acres.

### Square Kilometre (km^{2})

One square kilometre equals 100 hectares, 1,000,000 square meters, approximately 247.105 acres, or 0.386 square miles.

## Conversions

The controls below will convert the various units to and from metric. Enter a value in one of the boxes click outside the box and the remaining boxes in the row will show the results

sq inches | sq centimetres |

sq yards | sq metres |

sq miles | sq kilometres |

acres | hectares |

## References

David Haworth.