PSAD56 / UTM zone 20S to KML & KMZ

Good to know

• This is a southern-hemisphere grid: northings start at 10,000,000 m at the equator.
• Pick the UTM zone by longitude. Points outside the zone's area of use are flagged after conversion.
• Datum: Published 3-parameter shift (typically a few metres).

Convert a whole spreadsheet

1. Open the web app or the Windows app, and paste your rows from Excel or open a CSV file.
2. Under Coordinate system, search for “24880” and pick PSAD56 / UTM zone 20S.
3. Check one point you know on the map, then press Save KML or Save KMZ and open it in Google Earth.

Common mistakes with PSAD56 / UTM zone 20S

• Feet entered as metres. PSAD56 / UTM zone 20S is in metres. Coordinates copied from a drawing in feet must be converted first, or every point moves outwards from the grid's origin.
• Forgetting the datum. PSAD56 / UTM zone 20S is not on WGS 84: published 3-parameter shift (typically a few metres). Picking a WGS 84 grid with the same projection instead leaves the points off by that amount.
• Points outside the grid's area. PSAD56 / UTM zone 20S is meant for Bolivia between 66°W and 60°W. Points well outside that area convert with growing error; the converter flags them so you can choose the right grid.
• A local site grid. If every point is off by the same distance and direction, the drawing may be on a local site grid. Calibrate on three or more known control points instead.

New to this? Read how to convert easting and northing to latitude and longitude.