Convert coordinates from Indian 1975 (EPSG:4240) to WGS 84 (EPSG:4326) — official EPSG transformation parameters, accuracy and area of use, with a free in-browser converter.
The EPSG Geodetic Parameter Dataset defines 4 transformations between Indian 1975 (EPSG:4240) and WGS 84 (EPSG:4326). Each applies to a specific area — pick the one whose area of use covers your data.
| Parameter | Value | Unit |
|---|---|---|
| X-axis translation(tx) | 204.64 | metre |
| Y-axis translation(ty) | 834.74 | metre |
| Z-axis translation(tz) | 293.8 | metre |
Derived in 1995 at point RTSD181.
| Parameter | Value | Unit |
|---|---|---|
| X-axis translation(tx) | 293 | metre |
| Y-axis translation(ty) | 836 | metre |
| Z-axis translation(tz) | 318 | metre |
| X-axis rotation(rx) | 0.5 | arc-second |
| Y-axis rotation(ry) | 1.6 | arc-second |
| Z-axis rotation(rz) | -2.8 | arc-second |
| Scale difference(ds) | 2.1 | parts per million |
| Parameter | Value | Unit |
|---|---|---|
| X-axis translation(tx) | 209 | metre |
| Y-axis translation(ty) | 818 | metre |
| Z-axis translation(tz) | 290 | metre |
Derived at 62 stations. Accuracy 3m, 2m and 3m in X, Y and Z axes. Replaced by Indian 1975 to WGS 84 (2) (code 1304).
| Parameter | Value | Unit |
|---|---|---|
| X-axis translation(tx) | 210 | metre |
| Y-axis translation(ty) | 814 | metre |
| Z-axis translation(tz) | 289 | metre |
Derived at 62 stations. Accuracy 3m, 2m and 3m in X, Y and Z axes. Replaces Indian 1975 to WGS 84 (1) (code 1154).
The same transformation with common GIS tools and libraries:
from pyproj import Transformer
transformer = Transformer.from_crs("EPSG:4240", "EPSG:4326", always_xy=True)
x, y = transformer.transform(-73.9857, 40.7484)
print(x, y)geographic system using latitude and longitude on an ellipsoid · Area of use: Thailand - onshore and Gulf of Thailand
+proj=longlat +ellps=evrst30 +towgs84=210,814,289,0,0,0,0 +no_defs +type=crsMore about EPSG:4240 →
geographic system using latitude and longitude on an ellipsoid · Area of use: World (by country)
+proj=longlat +datum=WGS84 +no_defs +type=crsMore about EPSG:4326 →