# Template:Great circle distance

0

## Usage

Computes the w:great circle distance between two points, specified by the latitude and longitude, using the w:haversine formula.

`{{Great circle distance|latitude 1|longitude 1|latitude 2|longitude 2|radius of the planet in km (optional)|units=(optional)|precision=(optional)}}`

or

`{{Great circle distance|lat1=|long1=|lat2=|long2=|r=|units=|precision=}}`

• `latitude 1`, `longitude 1`, `latitude 2`, and `longitude 2` are the coordinates of your point. They should be specified as w:decimal degrees, not in degree-minute-second (DMS) notation, and South and West latitude and longitude should be expressed as negative numbers. You can use {{Decdeg}} to convert from DMS to decimal notation (e.g. `{{Great circle distance|{{decdeg|40|42|45.72}}|{{decdeg|-70|0|21.24}}|{{decdeg|34|2|60}}|{{decdeg|-118|15|0}}|units=mi}}` yields 2,654).
• The `radius of the planet in km` (`r=`) parameter defaults the average radius of the earth between the latitudes of the input coordinates (using {{Great circle distance/er}}). Because the earth is an w:ellipsoid, not a perfect sphere, the further your points are from each other, the less accurate your answer will be. You can substitute this value for the radius at your midpoint, if known, or use any other value (for example, you could use 3390 if you want distances on w:Mars, or 6371 if you want to use the mean earth radius).
• `precision` uses the same syntax as the unnamed precision parameter in Template:Convert.

## TemplateData

Computes the great circle distance between two points, specified by the latitude and longitude, using the haversine formula.

Template parameters

ParameterDescriptionTypeStatus
Latitude 1`lat1` `1`

Latitude of point 1 in decimal degrees

Default
0
Numberrequired
Longitude 1`long1` `2`

Longitude of point 1 in decimal degrees

Default
0
Numberrequired
Latitude 2`lat2` `3`

Latitude of point 2 in decimal degrees

Default
0
Numberrequired
Longitude 2`long2` `4`

Longitude of point 2 in decimal degrees

Default
0
Numberrequired
Radius`r` `5`

Radius of the planet in kilometers

Default
6373
Numberoptional
Units`units`

Units to output distance in (defaults to km). Can be any distance unit supported by [[:Template:Convert]]

Default
km
Stringoptional