GeoCAD Bridge

EPSG Library · Levant, Iraq and Turkey

EPSG:5258 — TUREF / TM42

Source: EPSG Dataset via PROJ 9.5.1 · Updated

Summary

EPSG:5258 (TUREF / TM42) is a projected coordinate reference system on the Turkish National Reference Frame datum using the Transverse Mercator method, with coordinates in metres. Area of use: Türkiye (Turkey) - between 40°30'E and 43°30'E, onshore.

  • Type: projected
  • Datum: Turkish National Reference Frame
  • Units: metre
  • Axes: X, Y

Definition

EPSG:5258 as published in the EPSG Dataset (PROJ 9.5.1).
PropertyValue
EPSG codeEPSG:5258
NameTUREF / TM42
TypeProjected CRS
DatumTurkish National Reference Frame
EllipsoidGRS 1980 (a = 6,378,137.000 m, 1/f = 298.257222)
Prime meridianGreenwich
Projection methodTransverse Mercator
AxesNorthing (X, north, metre); Easting (Y, east, metre)
ScopeCadastre, engineering survey, topographic mapping (large scale).
Bounding box40.5° to 43.5° longitude, 37.02° to 41.6° latitude

Area of use

Türkiye (Turkey) - between 40°30'E and 43°30'E, onshore.

Projection parameters

Transverse Mercator parameters.
ParameterValueUnit
Latitude of natural origin0degree
Longitude of natural origin42degree
Scale factor at natural origin1unity
False easting500,000metre
False northing0metre

Example coordinates

A WGS 84 point at longitude 42.0°, latitude 39.31° (inside the area of use) has these coordinates in EPSG:5258:

Computed with PROJ using the EPSG default operation: axis order change (2D) + Inverse of TUREF to WGS 84 (1) + 3-degree Gauss-Kruger CM 42E + axis order change (2D).
AxisValueUnit
X500,000.000m
Y4,352,919.701m

At this point the projection scale factor is 1.00000000 and the grid convergence is -0.000000°.

Open this conversion in the coordinate converter

Transformations to WGS 84

Candidate operations from the EPSG Dataset, best first as ranked by PROJ.
OperationAccuracyArea of use
axis order change (2D) + TUREF to WGS 84 (1) + axis order change (2D)1 mTürkiye (Turkey) - 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=0 +lon_0=42 +k=1 +x_0=500000 +y_0=0 +ellps=GRS80 +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=0 +lon_0=42 +k=1 +x_0=500000 +y_0=0 +ellps=GRS80 +units=m +towgs84=0,0,0 +no_defs

Datum shift from TUREF to WGS 84 (1) (EPSG accuracy 1 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["TUREF / TM42", BASEGEOGCRS["TUREF", DATUM["Turkish National Reference Frame", ELLIPSOID["GRS 1980",6378137,298.257222101, LENGTHUNIT["metre",1]]], PRIMEM["Greenwich",0, ANGLEUNIT["degree",0.0174532925199433]], ID["EPSG",5252]], CONVERSION["3-degree Gauss-Kruger CM 42E", METHOD["Transverse Mercator", ID["EPSG",9807]], PARAMETER["Latitude of natural origin",0, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8801]], PARAMETER["Longitude of natural origin",42, ANGLEUNIT["degree",0.0174532925199433], ID["EPSG",8802]], PARAMETER["Scale factor at natural origin",1, SCALEUNIT["unity",1], ID["EPSG",8805]], PARAMETER["False easting",500000, LENGTHUNIT["metre",1], ID["EPSG",8806]], PARAMETER["False northing",0, LENGTHUNIT["metre",1], ID["EPSG",8807]]], CS[Cartesian,2], AXIS["northing (X)",north, ORDER[1], LENGTHUNIT["metre",1]], AXIS["easting (Y)",east, ORDER[2], LENGTHUNIT["metre",1]], USAGE[ SCOPE["Cadastre, engineering survey, topographic mapping (large scale)."], AREA["Türkiye (Turkey) - between 40°30'E and 43°30'E, onshore."], BBOX[37.02,40.5,41.6,43.5]], ID["EPSG",5258]]

Downloads

FAQ

What is EPSG:5258?

EPSG:5258 (TUREF / TM42) is a projected coordinate reference system on the Turkish National Reference Frame datum using the Transverse Mercator method, with coordinates in metres. Area of use: Türkiye (Turkey) - between 40°30'E and 43°30'E, onshore.

Where can EPSG:5258 be used?

Its area of use is: Türkiye (Turkey) - between 40°30'E and 43°30'E, onshore.

Is EPSG:5258 in metres or degrees?

EPSG:5258 is projected, so coordinates are northing and easting in metres, not degrees.

How do I convert EPSG:5258 to latitude and longitude?

Transform from EPSG:5258 to EPSG:4326 (WGS 84). In GeoCAD Bridge open the coordinate converter with EPSG:5258 preselected, enter easting and northing, and choose WGS 84 as the target.

How accurate is the transformation from EPSG:5258 to WGS 84?

The most accurate EPSG transformation listed here is “axis order change (2D) + TUREF to WGS 84 (1) + axis order change (2D)”, with a stated accuracy of 1 m for Türkiye (Turkey) - onshore and offshore.. Always check the area of use before applying it.

Coordinate systems

Articles

Tools

References

  1. IOGP. EPSG Geodetic Parameter Dataset, epsg.org/crs_5258.
  2. PROJ 9.5.1 / pyproj 3.7.2, used to compute every value on this page.

Cite this page

GeoCAD Bridge. “EPSG:5258 — TUREF / TM42.” GeoCAD Bridge EPSG Library, updated 2026-10-05. https://www.geocadbridge.com/epsg/5258/