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EPSG Library · Global and web

EPSG:4978 — WGS 84

Source: EPSG Dataset via PROJ 9.5.1 · Updated

Summary

EPSG:4978 (WGS 84) is an Earth-centred, Earth-fixed geocentric CRS on the World Geodetic System 1984 ensemble datum with X, Y, Z coordinates in metres. Area of use: World. The datum is an ensemble with about 2.0 m accuracy, so precise work should name a specific realization.

  • Type: geocentric
  • Datum: World Geodetic System 1984 ensemble
  • Units: metre
  • Axes: X, Y, Z

Definition

EPSG:4978 as published in the EPSG Dataset (PROJ 9.5.1).
PropertyValue
EPSG codeEPSG:4978
NameWGS 84
TypeGeocentric CRS
DatumWorld Geodetic System 1984 ensemble (ensemble, accuracy ≈ 2.0 m)
EllipsoidWGS 84 (a = 6,378,137.000 m, 1/f = 298.257224)
Prime meridianGreenwich
AxesGeocentric X (X, geocentricX, metre); Geocentric Y (Y, geocentricY, metre); Geocentric Z (Z, geocentricZ, metre)
ScopeGeodesy. Navigation and positioning using GPS satellite system.
Bounding box-180° to 180° longitude, -90° to 90° latitude

Area of use

World.

Example coordinates

A WGS 84 point at longitude 0.0°, latitude 0.0° (inside the area of use) has these coordinates in EPSG:4978:

Computed with PROJ using the EPSG default operation.
AxisValueUnit
X6,378,137.000m
Y0.000m
Z0.000m

Definitions and downloads

PROJ string

+proj=geocent +datum=WGS84 +units=m +no_defs +type=crs

A PROJ string cannot carry every EPSG detail (axis order, datum ensemble, transformations). Prefer WKT2 or the EPSG code itself.

WKT2:2019
GEODCRS["WGS 84", ENSEMBLE["World Geodetic System 1984 ensemble", MEMBER["World Geodetic System 1984 (Transit)"], MEMBER["World Geodetic System 1984 (G730)"], MEMBER["World Geodetic System 1984 (G873)"], MEMBER["World Geodetic System 1984 (G1150)"], MEMBER["World Geodetic System 1984 (G1674)"], MEMBER["World Geodetic System 1984 (G1762)"], MEMBER["World Geodetic System 1984 (G2139)"], MEMBER["World Geodetic System 1984 (G2296)"], ELLIPSOID["WGS 84",6378137,298.257223563, LENGTHUNIT["metre",1]], ENSEMBLEACCURACY[2.0]], PRIMEM["Greenwich",0, ANGLEUNIT["degree",0.0174532925199433]], CS[Cartesian,3], AXIS["(X)",geocentricX, ORDER[1], LENGTHUNIT["metre",1]], AXIS["(Y)",geocentricY, ORDER[2], LENGTHUNIT["metre",1]], AXIS["(Z)",geocentricZ, ORDER[3], LENGTHUNIT["metre",1]], USAGE[ SCOPE["Geodesy. Navigation and positioning using GPS satellite system."], AREA["World."], BBOX[-90,-180,90,180]], ID["EPSG",4978]]

Downloads

FAQ

What is EPSG:4978?

EPSG:4978 (WGS 84) is an Earth-centred, Earth-fixed geocentric CRS on the World Geodetic System 1984 ensemble datum with X, Y, Z coordinates in metres. Area of use: World. The datum is an ensemble with about 2.0 m accuracy, so precise work should name a specific realization.

Where can EPSG:4978 be used?

Its area of use is: World.

What is the axis order of EPSG:4978?

By the EPSG definition: Geocentric X, Geocentric Y, Geocentric Z. Many GIS formats such as GeoJSON and KML store longitude first instead.

Coordinate systems

Articles

Tools

References

  1. IOGP. EPSG Geodetic Parameter Dataset, epsg.org/crs_4978.
  2. PROJ 9.5.1 / pyproj 3.7.2, used to compute every value on this page.

Cite this page

GeoCAD Bridge. “EPSG:4978 — WGS 84.” GeoCAD Bridge EPSG Library, updated 2026-10-05. https://www.geocadbridge.com/epsg/4978/