Units of length

Tip

All length units have helper methods ->asMetres(), ->add(), ->subtract(), ->multiply() and ->divide()

Tip

You can access the list of supported length units at runtime using Length::getSupportedSRIDs() or Length::getSupportedSRIDsWithHelp()

Metre

new Metre(float $length)
Length::makeUnit(float $length, Length::EPSG_METRE)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9001')

SI base unit for length.

Centimetre

new Centimetre(float $length)
Length::makeUnit(float $length, Length::EPSG_CENTIMETRE)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::1033')

Kilometre

new Kilometre(float $length)
Length::makeUnit(float $length, Length::EPSG_KILOMETRE)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9036')

Millimetre

new Millimetre(float $length)
Length::makeUnit(float $length, Length::EPSG_MILLIMETRE)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::1025')

International (modern) foot

new Foot(float $length)
Length::makeUnit(float $length, Length::EPSG_FOOT)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9002')

\(\frac{3048}{10000}\) metres.

US survey foot

new USSurveyFoot(float $length)
Length::makeUnit(float $length, Length::EPSG_US_SURVEY_FOOT)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9003')

\(\frac{12}{39.37}\) metres. Now deprecated by NIST who would prefer you use metres (or international feet if you can’t)

British foot

British foot (Benoit 1895 B)

British chain (Benoit 1895 B)

Length::makeUnit(float $length, Length::EPSG_BRITISH_CHAIN_BENOIT_1895_B)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9062')

Used in West Malaysian mapping.

British foot (Sear’s 1922)

new BritishFoot1922Sears(float $length)
Length::makeUnit(float $length, Length::EPSG_BRITISH_FOOT_SEARS_1922)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9041')

Used in East Malaysian and older New Zealand mapping.

British yard (Sear’s 1922)

new BritishYard1922Sears(float $length)
Length::makeUnit(float $length, Length::EPSG_BRITISH_YARD_SEARS_1922)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9040')

3 British feet.

British chain (Sear’s 1922)

new BritishChain1922Sears(float $length)
Length::makeUnit(float $length, Length::EPSG_BRITISH_CHAIN_SEARS_1922)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9042')

66 British feet.

British foot (Sear’s 1922 truncated)

British chain (Sear’s 1922 truncated)

new BritishChain1922SearsTruncated(float $length)
Length::makeUnit(float $length, Length::EPSG_BRITISH_CHAIN_SEARS_1922_TRUNCATED)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9301')

66 British Feet. Used in metrication of Malaya RSO grid.

British foot (1936)

new BritishFoot1936(float $length)
Length::makeUnit(float $length, Length::EPSG_BRITISH_FOOT_1936)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9095')

Also used for metric conversions in Ireland.

Clarke’s foot

new ClarkeFoot(float $length)
Length::makeUnit(float $length, Length::EPSG_CLARKES_FOOT)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9005')

Used in older Australian, southern African & British West Indian mapping.

Clarke’s yard

new ClarkeYard(float $length)
Length::makeUnit(float $length, Length::EPSG_CLARKES_YARD)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9037')

3 Clarke’s feet. Used in older Australian, southern African & British West Indian mapping.

Gold Coast foot

new GoldCoastFoot(float $length)
Length::makeUnit(float $length, Length::EPSG_GOLD_COAST_FOOT)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9094')

Used in Ghana and some adjacent parts of British west Africa prior to metrication, except for the metrication of projection defining parameters when British foot (Sear’s 1922) used.

Indian foot

new IndianFoot(float $length)
Length::makeUnit(float $length, Length::EPSG_INDIAN_FOOT)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9080')

Indian Foot = 0.99999566 British feet.

Indian yard

new IndianYard(float $length)
Length::makeUnit(float $length, Length::EPSG_INDIAN_YARD)
Length::makeUnit(float $length, 'urn:ogc:def:uom:EPSG::9084')

3 Indian Feet.