Convert coordinates from Tokyo (EPSG:4301) to WGS 84 (EPSG:4326) — official EPSG transformation parameters, accuracy and area of use, with a free in-browser converter.
Tokyo Datum (EPSG:4301) served Japan until 2002, defined on the Bessel 1841 ellipsoid with its origin in Azabu, Tokyo. Because the 19th-century triangulation absorbed local deflections of the vertical, Tokyo Datum positions are offset from WGS 84 by roughly 400 m — among the largest national datum shifts anywhere.
Japan replaced it with JGD2000 (EPSG:4612) and, after the 2011 Tōhoku earthquake, JGD2011 (EPSG:6668). EPSG publishes several Tokyo-to-WGS 84 transformations of differing scope and accuracy, fitted for Japan and for Korea, where the datum was also used.
Any Japanese dataset created before 2002 — paper maps, cadastre, utilities — should be assumed to be on Tokyo Datum until proven otherwise.
Try it: Tokyo Station, Japan
Input (EPSG:4301): 139.7671, 35.6812
The EPSG Geodetic Parameter Dataset defines 6 transformations between Tokyo (EPSG:4301) 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) | -147 | metre |
| Y-axis translation(ty) | 506 | metre |
| Z-axis translation(tz) | 687 | metre |
Derived at 29 stations. Accuracy 2m in each axis. Replaces Tokyo to WGS 84 (3) (code 1232).
| Parameter | Value | Unit |
|---|---|---|
| X-axis translation(tx) | -146.414 | metre |
| Y-axis translation(ty) | 507.337 | metre |
| Z-axis translation(tz) | 680.507 | metre |
Parameter values from Tokyo to JGD2000 (1) (code 15483). Assumes JGD2000 and WGS 84 can be considered the same to within the accuracy of the transformation.
| Parameter | Value | Unit |
|---|---|---|
| X-axis translation(tx) | -148 | metre |
| Y-axis translation(ty) | 507 | metre |
| Z-axis translation(tz) | 685 | metre |
Derived at 16 stations. Accuracy 8m, 5m and 8m in X, Y and Z axes.
| Parameter | Value | Unit |
|---|---|---|
| X-axis translation(tx) | -146 | metre |
| Y-axis translation(ty) | 507 | metre |
| Z-axis translation(tz) | 687 | metre |
Derived at 29 stations. Accuracy 8m, 5m and 8m in X, Y and Z axes. Replaced by Tokyo to WGS 84 (5) (code 1305).
| Parameter | Value | Unit |
|---|---|---|
| X-axis translation(tx) | -148 | metre |
| Y-axis translation(ty) | 507 | metre |
| Z-axis translation(tz) | 685 | metre |
Derived at 31 stations. Accuracy 20m, 5m and 20m in X, Y and Z axes.
| Parameter | Value | Unit |
|---|---|---|
| X-axis translation(tx) | -158 | metre |
| Y-axis translation(ty) | 507 | metre |
| Z-axis translation(tz) | 676 | metre |
Derived at 3 stations. Accuracy 20m, 5m and 20m in X, Y and Z axes.
The same transformation with common GIS tools and libraries:
from pyproj import Transformer
transformer = Transformer.from_crs("EPSG:4301", "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: Asia - Japan and Korea
+proj=longlat +ellps=bessel +towgs84=-146.414,507.337,680.507,0,0,0,0 +no_defs +type=crsMore about EPSG:4301 →
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 →