EPSG Library · Egypt

EPSG:22993 — Egypt 1907 / Purple Belt

Source: EPSG Dataset via PROJ 9.5.1 · Updated 2026-10-05

Summary

EPSG:22993 (Egypt 1907 / Purple Belt) is a projected coordinate reference system on the Egypt 1907 datum using the Transverse Mercator method, with coordinates in metres. Area of use: Egypt - onshore west of 29°E and north of approximately 28°11'N.

Type: projected
Datum: Egypt 1907
Units: metre
Axes: E, N

Definition

EPSG:22993 as published in the EPSG Dataset (PROJ 9.5.1).
Property	Value
EPSG code	EPSG:22993
Name	Egypt 1907 / Purple Belt
Type	Projected CRS
Datum	Egypt 1907
Ellipsoid	Helmert 1906 (a = 6,378,200.000 m, 1/f = 298.3)
Prime meridian	Greenwich
Projection method	Transverse Mercator
Axes	Easting (E, east, metre); Northing (N, north, metre)
Scope	Engineering survey, topographic mapping.
Bounding box	24.7° to 29° longitude, 28.18° to 31.68° latitude

Area of use

Egypt - onshore west of 29°E and north of approximately 28°11'N.

Projection parameters

Transverse Mercator parameters.
Parameter	Value	Unit
Latitude of natural origin	30	degree
Longitude of natural origin	27	degree
Scale factor at natural origin	1	unity
False easting	700,000	metre
False northing	200,000	metre

Example coordinates

A WGS 84 point at longitude 26.85°, latitude 29.93° (inside the area of use) has these coordinates in EPSG:22993:

Computed with PROJ using the EPSG default operation: unavailable until proj_trans is called.
Axis	Value	Unit
E	685,361.622	m
N	192,228.889	m

At this point the projection scale factor is 1.00000259 and the grid convergence is -0.074841°.

Open this conversion in the coordinate converter

Transformations to WGS 84

Candidate operations from the EPSG Dataset, best first as ranked by PROJ.
Operation	Accuracy	Area of use
axis order change (2D) + Egypt 1907 to WGS 84 (4) + axis order change (2D)	1.2 m	Egypt - onshore and offshore.
axis order change (2D) + Egypt 1907 to WGS 72 (1) + WGS 72 to WGS 84 (1) + axis order change (2D)	7 m	Egypt - onshore and offshore.
axis order change (2D) + Egypt 1907 to WGS 84 (1) + axis order change (2D)	11 m	Egypt - onshore and offshore.

Transformations change the datum, so each has an accuracy and an area of use. Choose the most accurate one that covers your data and record its name. See datum transformations.

Definitions and downloads

PROJ string

+proj=tmerc +lat_0=30 +lon_0=27 +k=1 +x_0=700000 +y_0=200000 +ellps=helmert +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.

Proj4js definition used by the converter

+proj=tmerc +lat_0=30 +lon_0=27 +k=1 +x_0=700000 +y_0=200000 +ellps=helmert +units=m +towgs84=-130,110,-13 +no_defs

Datum shift from Egypt 1907 to WGS 84 (1) (EPSG accuracy 11 m), the best single Helmert operation for this area of use. Where PROJ prefers a grid-based or multi-step operation (see the table above), results can differ by up to that operation's accuracy.

WKT2:2019

PROJCRS["Egypt 1907 / Purple Belt", BASEGEOGCRS["Egypt 1907", DATUM["Egypt 1907", ELLIPSOID["Helmert 1906",6378200,298.3, LENGTHUNIT["metre",1]]], PRIMEM["Greenwich",0, ANGLEUNIT["degree",0.0174532925199433]], ID["EPSG",4229]], CONVERSION["Egypt Purple Belt", METHOD["Transverse Mercator", ID["EPSG",9807]], PARAMETER["Latitude of natural origin",30, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8801]], PARAMETER["Longitude of natural origin",27, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8802]], PARAMETER["Scale factor at natural origin",1, SCALEUNIT["unity",1], ID["EPSG",8805]], PARAMETER["False easting",700000, LENGTHUNIT["metre",1], ID["EPSG",8806]], PARAMETER["False northing",200000, LENGTHUNIT["metre",1], ID["EPSG",8807]]], CS[Cartesian,2], AXIS["(E)",east, ORDER[1], LENGTHUNIT["metre",1]], AXIS["(N)",north, ORDER[2], LENGTHUNIT["metre",1]], USAGE[ SCOPE["Engineering survey, topographic mapping."], AREA["Egypt - onshore west of 29°E and north of approximately 28°11'N."], BBOX[28.18,24.7,31.68,29]], ID["EPSG",22993]]

Downloads

22993.prj — ESRI WKT for shapefiles
22993.wkt — OGC WKT2:2019

FAQ

What is EPSG:22993?

Where can EPSG:22993 be used?

Its area of use is: Egypt - onshore west of 29°E and north of approximately 28°11'N.

Is EPSG:22993 in metres or degrees?

EPSG:22993 is projected, so coordinates are easting and northing in metres, not degrees.

How do I convert EPSG:22993 to latitude and longitude?

Transform from EPSG:22993 to EPSG:4326 (WGS 84). In GeoCAD Bridge open the coordinate converter with EPSG:22993 preselected, enter easting and northing, and choose WGS 84 as the target.

How accurate is the transformation from EPSG:22993 to WGS 84?

The most accurate EPSG transformation listed here is “axis order change (2D) + Egypt 1907 to WGS 84 (4) + axis order change (2D)”, with a stated accuracy of 1.2 m for Egypt - onshore and offshore.. Always check the area of use before applying it.

Coordinate systems

Articles

Tools

References

IOGP. EPSG Geodetic Parameter Dataset, epsg.org/crs_22993.
PROJ 9.5.1 / pyproj 3.7.2, used to compute every value on this page.

Cite this page

GeoCAD Bridge. “EPSG:22993 — Egypt 1907 / Purple Belt.” GeoCAD Bridge EPSG Library, updated 2026-10-05. https://www.geocadbridge.com/epsg/22993/