Country Coordinate Systems
Egypt 1907 Datum and the Egyptian Belts
Summary
Egypt 1907 is Egypt’s classical geodetic datum on the Helmert 1906 ellipsoid (EPSG:4229). Projected coordinates use four Transverse Mercator belts: Blue (EPSG:22991, east of 33°E), Red (EPSG:22992, 29°E–33°E, including Cairo), Purple (EPSG:22993) and Extended Purple (EPSG:22994) west of 29°E. The best EPSG transformation to WGS 84 is accurate to about 1.2 m.
Definition
Egypt 1907: the geodetic datum of Egypt’s classical triangulation, on the Helmert 1906 ellipsoid (a = 6 378 200 m, 1/f = 298.3).
- Ellipsoid: Helmert 1906
- Geographic: EPSG:4229
- Red Belt: EPSG:22992
- Best to WGS 84: 1.2 m
Egyptian belts
| Belt | EPSG | Area of use |
|---|---|---|
| Blue Belt | 22991 | East of 33°E, Gulf of Suez |
| Red Belt | 22992 | 29°E – 33°E, Cairo, Nile Delta |
| Purple Belt | 22993 | West of 29°E, north of ≈28°11′N |
| Extended Purple Belt | 22994 | West of 29°E, south of ≈28°11′N |
Transformations to WGS 84
| Transformation | Method | Accuracy |
|---|---|---|
| Egypt 1907 to WGS 84 (1) | 3-parameter (−130, 110, −13 m) | 11 m |
| Egypt 1907 to WGS 84 (2) | Concatenated | 6 m |
| Egypt 1907 to WGS 84 (4) | Molodensky–Badekas | 1.2 m |
Worked example
Cairo (30.0444° N, 31.2357° E, WGS 84) in Egypt 1907 / Red Belt (EPSG:22992) is E 637,570.9 m, N 814,926.7 m using the best EPSG transformation, and in WGS 84 / UTM 36N (EPSG:32636) E 329,899.6 m, N 3,325,016.7 m.
FAQ
Which belt is Cairo in?
The Red Belt, EPSG:22992.
Does Egypt use UTM?
Yes, WGS 84 / UTM zones 35N–37N are widely used for modern projects, with 36N covering Cairo and the Nile valley.
Related tools and articles
Tools
- Egypt ConverterEgyptian belts and UTM zones.
- Coordinate TransformationConvert between EPSG coordinate systems.
Articles
- Transverse Mercator ProjectionThe Transverse Mercator (TM) projection wraps a cylinder around the Earth touching a chosen central meridian. …
- Datum Transformations: Helmert, Grids and AccuracyA datum transformation converts coordinates between two geodetic datums, for example Ain el Abd 1970 to WGS 84…
- EgyptReference topic
- UTM Zones: Find the Right Zone and EPSG CodeThe UTM zone of a point is floor((longitude + 180)/6) + 1, and its central meridian is 6·zone − 183°. In the M…
References
- IOGP. EPSG Geodetic Parameter Dataset, epsg.org.
- IOGP. Geomatics Guidance Note 7-2: Coordinate Conversions and Transformations including Formulas, IOGP Report 373-7-2.
Cite this page
GeoCAD Bridge. “Egypt 1907 Datum and the Egyptian Belts.” GeoCAD Bridge Knowledge Center, updated 2026-10-05. https://www.geocadbridge.com/knowledge/coordinate-systems-egypt-1907/