Map Features/Units

Many keys expect their values in certain units, e.g. length is usually specified in metres. The unit of the value can either be given explicitly (e.g. maxspeed=50 mph), or, if no unit is specified, a certain unit will be assumed (e.g. for width=2 the unit metre is assumed).

This article presents an overview of such units which can be explicitly specified, as well as units which are implicitly assumed if no unit is explicitly specified.

Contents 1 Assumed units: default units 2 Explicit specifications 2.1 Length 2.2 Speed 2.3 Weight 3 Common mistakes

Assumed units: default units

If no unit is explicitly specified, the following units are assumed:

Measure	Default unit	Explicit specification	Example
Length	Metre	m	width=3 means a width of 3 metres
Speed	Kilometres/hour	km/h	maxspeed=100 means a speed limit of 100 Kilometres_per_hour
Weight	Ton	t	maxweight=3.5 means a weight limit of 3.5 tons

Explicit specifications

The following units can be explicitly specified by adding them after the numeric value, separated by a space (with the exception of the combined specification of feet and inches):

Length

Explicit specification	Unit	Example	Alias(e) (discouraged)	Conversion to default unit
m	Metre	height=3 m	metre, metres	-
km	Kilometre	width=0.2 km	kilometre, kilometres, kilometer, kilometers	Multiply by 0.001
mi	Mile	width=1.45 mi	mile, miles	Multiply by 0.000621371192 or divided by 1,609.344
<feet>'<inch>"	Feet and inches combined	maxwidth=12'5"		Multiply the feet by 12, add the inches and multiply the result by 0.0254

Speed

Explicit specification	Unit	Example	Alias(e) (discouraged)	Conversion to default unit
km/h	Kilometre/hour	minspeed=80 km/h	kph, kmph	-
mph	Miles/hour	maxspeed=60 mph		Multiply by 1.609344
knots	Knots	maxspeed=10 knots		Multiply by 1.852

Weight

Explicit specification	Unit	Example	Alias(e) (discouraged)	Conversion to default unit
t	Ton	maxweight=3 t		-

Common mistakes

The following table presents examples of incorrect tags together with their correct notation.

Incorrect	Explanation	Correct
height=6m	Missing space between numeric value and unit.	height=6 m
maxweight=3,5	Using the comma as wrong decimal separator.	maxweight=3.5
width=12' 6"	There should be no space between the specification of feet and inches.	width=12'6"