Convert coordinates from SAD69 (EPSG:4618) to SIRGAS 2000 (EPSG:4674) — official EPSG transformation parameters, accuracy and area of use, with a free in-browser converter.
SAD69 (South American Datum 1969, EPSG:4618) was the continental datum of South America, defined on the GRS 1967 ellipsoid with its origin at Chuá, Brazil. Brazilian mapping used it for decades, including the UTM SAD69 zones.
SIRGAS 2000 (EPSG:4674) is the modern ITRF-based frame that legally replaced SAD69 in Brazil in 2015 — all official Brazilian geodata is now SIRGAS 2000. The published EPSG transformations implement IBGE's official parameters at metre-level accuracy.
The shift is around 60–70 m in Brazil, so unconverted SAD69 data is immediately visible against satellite imagery.
Try it: Brasília, Brazil
Input (EPSG:4618): -47.8825, -15.7942
The EPSG Geodetic Parameter Dataset defines 2 transformations between SAD69 (EPSG:4618) and SIRGAS 2000 (EPSG:4674). Each applies to a specific area — pick the one whose area of use covers your data.
Grid file: SAD69_003.gsb
For IBGE, in onshore east and south Brazil only, replaces SAD69 to SIRGAS 2000 (1) (tfm code 15485) for pre-1996 data based on the classical geodetic network. May be used as transformation between SAD69 and WGS 84 - see tfm code 5542.
| Parameter | Value | Unit |
|---|---|---|
| X-axis translation(tx) | -67.35 | metre |
| Y-axis translation(ty) | 3.88 | metre |
| Z-axis translation(tz) | -38.22 | metre |
Accuracy generally better than 1m except in Amazon basin where it degenerates to 5m. May be used as CT between SAD69(96) and SIRGAS 2000 and between SAD69 and WGS 84 - see tfm codes 5881 and 5882. Used by Petrobras and ANP throughout Brazil from 1994.
The same transformation with common GIS tools and libraries:
from pyproj import Transformer
transformer = Transformer.from_crs("EPSG:4618", "EPSG:4674", 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: South America - SAD69 by country
+proj=longlat +ellps=aust_SA +no_defs +type=crsMore about EPSG:4618 →
geographic system using latitude and longitude on an ellipsoid · Area of use: Latin America - SIRGAS 2000 by country
+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs +type=crsMore about EPSG:4674 →