Convert Chatham Islands 1979 to NZGD2000

Convert coordinates from Chatham Islands 1979 (EPSG:4673) to NZGD2000 (EPSG:4167) — official EPSG transformation parameters, accuracy and area of use, with a free in-browser converter.

From

Input (lon, lat (decimal degrees))

Output (lon, lat (decimal degrees))

Direct link to this transformation: epsgtransform.com/transform/epsg-4673-to-epsg-4167

Official EPSG transformation from Chatham Islands 1979 to NZGD2000

The EPSG Geodetic Parameter Dataset defines 1 transformation between Chatham Islands 1979 (EPSG:4673) and NZGD2000 (EPSG:4167). Its parameters, accuracy and area of use are listed below.

CI1979 to NZGD2000 (1)

EPSG:1082±2 m

Method:: Coordinate Frame rotation (geog2D domain)
Area of use:: New Zealand - Chatham Islands group
Scope:: (null/copy) Approximation for medium and low accuracy applications assuming equality between plate-fixed static and earth-fixed dynamic CRSs, ignoring static/dynamic CRS differences.

Parameter	Value	Unit
X-axis translation(tx)	174.05	metre
Y-axis translation(ty)	-25.49	metre
Z-axis translation(tz)	112.57	metre
X-axis rotation(rx)	0	arc-second
Y-axis rotation(ry)	0	arc-second
Z-axis rotation(rz)	-0.554	arc-second
Scale difference(ds)	0.2263	parts per million

Parameter vales are from CI1979 to WGS 84 (1) (code 1081) assuming that WGS 84 is equivalent to NZGD2000 within the accuracy of the transformation.

Convert EPSG:4673 to EPSG:4167 in code

The same transformation with common GIS tools and libraries:

from pyproj import Transformer

transformer = Transformer.from_crs("EPSG:4673", "EPSG:4167", always_xy=True)
x, y = transformer.transform(-73.9857, 40.7484)
print(x, y)

Source: EPSG:4673 — Chatham Islands 1979

geographic system using latitude and longitude on an ellipsoid · Area of use: New Zealand - Chatham Islands group

+proj=longlat +ellps=intl +towgs84=174.05,-25.49,112.57,0,0,0.554,0.2263 +no_defs +type=crs

More about EPSG:4673 →

Target: EPSG:4167 — NZGD2000

geographic system using latitude and longitude on an ellipsoid · Area of use: New Zealand

+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs +type=crs

More about EPSG:4167 →

Frequently asked questions

How accurate is converting Chatham Islands 1979 to NZGD2000?: The most accurate official EPSG transformation between these systems is accurate to about ±2 m within its stated area of use. Browser-based converters approximate datum shifts with Helmert parameters; for surveying-grade work apply the official transformation in a desktop GIS.
Does my data leave the browser when I use this converter?: No. All coordinate transformations are computed locally in your browser using proj4js. The coordinates you enter are never transmitted to any server.

Need the reverse? Convert EPSG:4167 to EPSG:4673 →