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Convert NAD27 to NAD83(CSRS)v3

Convert coordinates from NAD27 (EPSG:4267) to NAD83(CSRS)v3 (EPSG:8240) — official EPSG transformation parameters, accuracy and area of use, with a free in-browser converter.

Direct link to this transformation: epsgtransform.com/transform/epsg-4267-to-epsg-8240

Official EPSG transformations from NAD27 to NAD83(CSRS)v3

The EPSG Geodetic Parameter Dataset defines 4 transformations between NAD27 (EPSG:4267) and NAD83(CSRS)v3 (EPSG:8240). Each applies to a specific area — pick the one whose area of use covers your data.

NAD27 to NAD83(CSRS)v3 (6)

EPSG:9108±1 mBest accuracy
Method:
NTv2
Area of use:
Canada - Ontario - Toronto
Scope:
Geodesy.

Grid file: TO27CSv1.GSB

Derived through NAD83(CSRS)v3 but within accuracy of transformation may be assumed to apply to any version. For Ontario excluding Toronto use NAD27 to NAD83(CSRS) (5) (CT code 9107). Previously available from Land Information Ontario as TOR27CSv1.GSB.

NAD27 to NAD83(CSRS)v3 (5)

EPSG:9107±1.5 m
Method:
NTv2
Area of use:
Canada - Ontario ex. Toronto
Scope:
Geodesy.

Grid file: ON27CSv1.GSB

Derived through NAD83(CSRS)v3 but within accuracy of transformation may be assumed to apply to any version. For Toronto use NAD27 to NAD83(CSRS) (6) (CT code 9108).

NAD27 to NAD83(CSRS)v3 (8)

EPSG:9113±1.5 m
Method:
NTv2
Area of use:
Canada - British Columbia - CRD
Scope:
Geodesy.

Grid file: CRD27_00.GSB

Derived through NAD83(CSRS)v3.

NAD27 to NAD83(CSRS)v3 (9)

EPSG:9114±1.5 m
Method:
NTv2
Area of use:
Canada - British Columbia - north Vancouver Is
Scope:
Geodesy.

Grid file: NVI27_05.GSB

Derived through NAD83(CSRS)v3.

Convert EPSG:4267 to EPSG:8240 in code

The same transformation with common GIS tools and libraries:

from pyproj import Transformer

transformer = Transformer.from_crs("EPSG:4267", "EPSG:8240", always_xy=True)
x, y = transformer.transform(-73.9857, 40.7484)
print(x, y)

Source: EPSG:4267 — NAD27

geographic system using latitude and longitude on an ellipsoid · Area of use: North America - NAD27

+proj=longlat +datum=NAD27 +no_defs +type=crs
More about EPSG:4267 →

Target: EPSG:8240 — NAD83(CSRS)v3

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

+proj=longlat +ellps=GRS80 +no_defs +type=crs
More about EPSG:8240 →

Frequently asked questions

How accurate is converting NAD27 to NAD83(CSRS)v3?
The most accurate official EPSG transformation between these systems is accurate to about ±1 m within its stated area of use. Browser-based converters approximate datum shifts with Helmert parameters; for surveying-grade work apply the official transformation (including the grid-shift files listed below) 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:8240 to EPSG:4267 →