Coordinate Converter — WGS84, UTM, ITRF, ED50

Understanding Coordinate Systems

The same point on Earth can be described by very different sets of numbers depending on the coordinate reference system (CRS) you use. A CRS defines two things: a datum (the model of the Earth's shape and where it is anchored) and, often, a projection (how the curved surface is flattened onto a map). Mixing systems without converting is one of the most common sources of error in GIS work — points can land hundreds of metres away from where they belong. Below are the systems this converter handles most often.

WGS84 — The GPS Standard

WGS84 (EPSG:4326) is the global datum behind GPS, smartphones, and almost every web map. Its coordinates are geographic — plain latitude and longitude in decimal degrees, for example 41.0082, 28.9784 for Istanbul. If your data came from a phone, a GPS receiver, or an online map, it is almost certainly WGS84. Use it whenever you need a single, worldwide reference that everyone understands.

UTM — Metres Instead of Degrees

The Universal Transverse Mercator system slices the globe into narrow north–south zones and projects each one separately, so positions are expressed in metres (easting and northing) rather than degrees. This makes distance and area calculations straightforward, which is why surveyors and engineers prefer it. Turkey falls in 6-degree UTM zones 35–37 (and in finer 3-degree zones for cadastral work). You pick UTM when you need to measure on the ground, not just locate on a globe.

ED50 — Legacy European Maps

ED50 (European Datum 1950) is an older datum still embedded in many historical Turkish and European maps, cadastral records, and infrastructure plans. Because it is anchored differently from WGS84, the same coordinates can sit 200–300 metres off in Turkey if you treat ED50 data as WGS84. Whenever you combine archival maps with modern GPS data, a correct ED50 ↔ WGS84 conversion is essential.

ITRF96 — High-Precision Modern Geodesy

ITRF96 is the high-accuracy reference frame underlying Turkey's national TUREF system. For everyday GIS it is effectively identical to WGS84 (the difference is at the centimetre level), but for geodetic surveying, deformation monitoring, or any centimetre-grade work, the specific ITRF realisation and epoch matter and should be stated explicitly.

What Is an EPSG Code?

An EPSG code is a short numeric identifier for a coordinate system, maintained in a public registry — for instance 4326 for WGS84 or 23036 for an ED50 UTM zone. Instead of describing a datum and projection in words, you can name the EPSG code and any GIS tool will know exactly what you mean. If you are unsure which code applies to your data, the EPSG Code Finder can help you identify it.