Egypt coordinate converter
Red, Blue, and Purple Belts (Egypt 1907) ↔ WGS84 ↔ UTM 35/36 — official EPSG parameters and the published datum shift.
Converter
Egyptian CRS: quick reference
Egypt historically works on the Egypt 1907 datum (Helmert 1906 ellipsoid) with a Transverse Mercator split into three belts: Red for the centre (31°E), Blue for the east and Sinai (35°E), Purple for the west (27°E). Modern GNSS work observes on WGS84 and is often delivered in UTM zones 35/36.
The costliest site error is mixing datums: a point moved from a legacy sheet to a GPS rover without the shift lands ~130 m off. This tool applies the published shift (EPSG::1148) both ways and warns when a point falls outside Egypt — the classic symptom of swapped axes.
For centimetre-grade work — stake-out, control networks, Scan-to-BIM — you need geodetic observation and a local fit. Request a scoped quote.
FAQ
- What is the Egyptian Red Belt?
- The Red Belt is an Egyptian Transverse Mercator projection on the Egypt 1907 datum with central meridian 31°E (EPSG:22992). It covers central Egypt and the Nile Valley and is the most common grid on Egyptian survey sheets.
- When do I use the Blue or Purple Belt?
- Blue (EPSG:22991, 35°E) for eastern Egypt and Sinai; Purple (EPSG:22993, 27°E) for the west; Extended Purple (EPSG:22994) for the south-west. Follow the project’s reference sheets.
- Why does GPS disagree with old sheet coordinates by ~100 m?
- GPS reads WGS84 while legacy Egyptian sheets sit on Egypt 1907 — the datums differ by roughly 130 m in Egypt. A proper datum shift is required, not just re-projection.
- How accurate is this tool?
- It applies the published 3-parameter shift (EPSG::1148: dX=-130, dY=+110, dZ=-13), good to a few metres. Centimetre-grade work (stake-out, network adjustment) needs geodetic observation and a local fit — a service we provide.
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