Key:ele

ele=*

Elevation (height above sea level) of a point, in metres. This is mainly intended for mountain peaks but could also be used for elevation of airport runways and many other objects. For OpenStreetMap, this value should be in metres above above mean sea level as defined by the EGM96 geoid model. This elevation is usually very close to national "above sea level" systems with differences < 1m. This is not the height above the WGS84 ellipsoid (see Geoid) which is shown as raw elevation by some satellite navigation devices and which can differ from geoid elevation by up to 100 m.

In case of buildings and other man_made structures that stand on the ground, use the elevation of the surrounding ground, not of the structure itself (e.g. don't tag the roof top or the tip of a tower, but tag the ground level and add the height with the tag height=*).

Basics

OSM currently records points with their latitude and longitude (x/y coordinates), elevations are only recorded for features where they are significant like for peaks or surveyed points. Where this is done, the elevation above geoid (EGM96) is stored in the ele=* key. OpenStreetMap does not try to be a general elevation database so you should not tag elevation of nodes with no other tags and no specific meaning that suggests an elevation value is significant information in this case.

A proposal for vertical datums other than the EGM96 geoid is to store them in keys such as ele:xyz=*, where xyz is the map datum and elevation is specified in metres.

The elevation in a local datum can be tagged as ele:local=*, with elevation specified in metres.

Sources for elevation values can be signs or values from literature. Such values should however also be checked for plausibility since elevation signs and official mountain heights are known to be frequently inaccurate. Another source of elevation data is GPS traces but elevation values from these are usually much less accurate than the horizontal position. You also need to make sure values are in the correct coordinate system or converted as necessary in case of ellipsoid based elevations.

Another source of elevation data are gridded elevation data sets. Such are often used in outdoor maps to render relief, like OpenCycleMap and Reit- und Wanderkarte and elevation values can be determined from displaying these maps as a background layer in editors. Beware however that such data sets contain a significant amount of noise and errors and absolute elevation values can easily be off by 50 metres.

In general elevation information with sub-metre accuracy is rarely verifiable so elevations should usually be specified in integer metres.

National reference systems

Elevations posted on official signs are usually relative to the national reference system of the respective country and have to be converted to WGS84/EGM96.

Country	Standard	Common name	Heights	Tide gauge	Reference point	Conversion
Australia	Australian Height Datum	Metres above mean sea level		32 distinct tidal references points on Australian coastline.	Ausgeoid09.	Conversion calculator online
Austria		Meter über Adria (m ü. Adria) (metres above Adriatic)	Normal-orthometric	Trieste 1875	Hutbiegl
Belgium		meter boven Oostende Peil (m O.P.) (metres above Oostende tide gauge)	Orthometric	Ostende	Ostende
Czech Republic	Bpv (Baltic Sea vertical datum)	metrů nad mořem (m n.m.) (metres above sea level)	Normal (Molodenskii's)	Kronstadt	Kronstadt, Russia
Estonia	BK77		Normal	Kronstadt	Kronstadt	[2]
Finland	N43,N60,N2000		Orthometric	Helsinki	Helsinki	[3]
France (mainland)	NGF-IGN69	mètres au-dessus du niveau de la mer (m) (metres above sea level)	Normal	Marseille	Marseille	[4]
France (Corsica)	NGF-IGN78	mètres au-dessus du niveau de la mer (m) (metres above sea level)	Normal	Ajaccio	Ajaccio	[5]
Germany *)	DHHN2016	Meter über Normalhöhennull [6]	Normal	Amsterdam	Wallenhorst
Former West Germany *)	DHHN12	Meter über Normalnull	Normal-orthometric	Amsterdam	Hoppegarten (near Müncheberg)
Former East Germany *)	SNN76	Meter über Höhennull (m ü. HN)	Normal	Kronštadt	Hoppegarten (near Müncheberg)
Hungary		Tengerszint feletti magasság	Normal	Kronštadt	Nadap
Ireland		metres above sea level (m ASL / m a.s.l.)	Orthometric	Malin Head	Malin Head
Italy		metri sul livello del mare (m s.l.m.) (metres above sea level)	Orthometric	Genoa	Genoa
Japan **)		Tōkyō-wan heikin kaimen (東京湾平均海面) (Tokyo Peil, T.P.)	Orthometric	Chiyoda, Tokyo	Nihon suijin genten (日本水準原点), 24.3900m **)
Liechtenstein	LN02	Meter über Meer (m ü. M.) (metres above sea level)		Marseille	Geneva
Luxemburg			Orthometric	Amsterdam	Amsterdam
Netherlands		meter boven/onder NAP (m NAP) (metres above/under NAP)	Orthometric	Amsterdam	Amsterdam
Norway		meter over havet (moh.) (meters above sea level)	Normal-orthometric	Tregde	Tregde
Poland		metry nad poziomem morza (m n.p.m.)	Normal	Kronštadt
Portugal		Nível médio do mar adotado (NMA)	Orthometric	Cascais	Datum Altimétrico Nacional de 1938 (Cascais)
Russia	BS1977	vysota (metry) nad urovnem morja (высота (метры) над уровнем моря) (elevation/metres above sea level)	Normal	Kronstadt	Kronstadt	The pseudo-geoid model EGM2008BALT is available for St. Petersburg / Kronstadt area [7]
Slovakia		metrov nad morom (m n.m.) (metres above sea level)	Normal	Kronštadt
Slovenia			Normal-orthometric	Trieste 1900	Ruse
Spain		metros sobre el nivel del mar (msnm) (metres above sea level)	Orthometric	Alicante	Alicante
Sweden	RH2000	Meter över havet (m ö.h.) (metres above sea level)	Normal	Amsterdam
Switzerland ***)	LN02	Meter über Meer (m ü. M.) (meters above sea level)		Marseille	Geneva
Turkey			Normal-orthometric	Antalya	Antalya
UK - Great Britain	Ordnance Datum Newlyn	metres above sea level (m ASL / m a.s.l.)	Orthometric	Newlyn, 1915 to 1921	Newlyn	OSGM02, Coordinate transformer
UK - Northern Ireland	Belfast Ordnance Datum	metres above sea level (m ASL / m a.s.l.)	Orthometric	Clarendon Lock, Belfast, 1951 to 1956.	Clarendon Lock, Belfast
Former Yugoslavia		Nadmorska visina (m/nv, ~metres above Adriatic)	Normal-orthometric	Trieste 1875/1900

*) DHHN92 was adopted gradually after reunification. Even newer topograpic maps may still use the former reference systems.
Former East Germany used DHHN-12 on the territory of East Berlin, in rail contexts and for landlocked waterbodies.

**) National authorities use this datum only for the four main islands of Hokkaidō, Honshū, Shikoku, Kyūshū and associated islands. For Sado, Oki, Tsushima, as well as for the Izu, Ogasawara and Ryūkyū islands, the mean sea level of a nearby coast or bay is used. For example, the reference point for Miyake-jima, which belongs to the Izu islands, is the mean sea level of Ako Bay on the western coast of the island.

***) LN02 remains in force. For LHN95, which uses orthometric elevations, the reference altitude of Repère Pierre du Niton was kept.

Example

The height of Breithorn in Switzerland is 4 164 metres. It could be mapped as:

natural=peak

name=Breithorn

ele=4164

The height of rail tracks in Tanggula railway station is 5 068 metres. It could be mapped as:

railway=station

name=唐古拉

name:bo=གདང་ལ་།

name:en=Tanggula

name:zh=唐古拉

ele=5068

Local units

It's been noted that some elevations are more conspicuous than others, and the requirement that key:ele be in metres is unhelpful for denotation on mountain peaks in non-metric areas. Since locals in the United States (and certainly elsewhere) think of things like mountain elevations strictly in feet, there seems to be no good way to address this with the current framework.

• It's tempting to enter an elevation with a unit of measure ("3045 feet") but the tag must be in metres
• Some software relies on this tag being numeric metres

There is likely no good solutions to this without using a separate tag for tagging height in local units. As of September 2021, ele:ft=* is used on over 2,300 features, while about 500 features are tagged with feet or inches in ele=*.

See also

• layer=* - used to mark layering of map elements
• height=* - used to mark how tall a map object is
• alt=* - Proposal to mark exact altitudes concerning to the reference system of heights. Deprecated.
• man_made=survey_point
• ele:wgs84=* an explicit wgs84 elipsodial height
• ele:local=* unclear meaning
• Proposed_features/ele:regional - a proposal to tag ele in the regionally common system and units