A spreadsheet of coordinates is just a table until you put it on a map. Here's how to turn CSV or Excel rows into Google Earth placemarks — and avoid the one mistake that dumps everything into the ocean.
To place points on a map, each row needs two coordinate columns: a latitude and a longitude. They can be named lat/lon, latitude/longitude, y/x — common headings are detected automatically. Any other columns (name, address, notes) become the placemark's attributes.
A spreadsheet this simple is enough: a header row of name,lat,lon, then one row per location such as Eiffel Tower,48.8584,2.2945. Everything else is optional. Add columns for site ID, category, depth, owner or date and they'll ride along as attributes you can see in the Google Earth popup.
Decimal degrees (48.8584) is the safest and most universal. Degrees-minutes-seconds (48°51'30"N) and degrees-decimal-minutes (48°51.5'N) are common on GPS units and survey sheets — if your sheet holds those, run them through the coordinate converter first, or split them into clean decimal columns. Avoid mixing formats within one column; that's a reliable way to lose rows.
Surveyors and engineers often work in metres — UTM eastings and northings, or a national grid. Those are not latitude and longitude, and Google Earth only understands WGS84 lat/long. Values like 451234 and 5411234 are the giveaway. You'll need to tell the converter which coordinate system those metres are in (for example EPSG:32631 for UTM zone 31N) so it can reproject them properly.
Three things save most of the pain. First, make sure row 1 is a genuine header row — merged title cells or a blank first row confuse column detection. Second, delete summary or total rows at the bottom; they have no coordinates and become stray features. Third, check the coordinate columns are stored as numbers, not text — Excel sometimes keeps them as text after a paste, and a leading apostrophe or a comma decimal separator will stop them parsing.
The single most common error is putting longitude where latitude belongs. Latitude runs −90 to 90; longitude runs −180 to 180. If your points land in the wrong hemisphere, swap the two columns. The live preview makes this obvious before you ever download — that's exactly why it's there.
Use the range test. Any value whose magnitude is above 90 must be a longitude, because latitude can't exceed 90. So if one column contains 120.5 and the other contains 31.2, the 120.5 is longitude. And remember the sign convention: negative latitude is southern hemisphere, negative longitude is west of Greenwich.
Inside a KML file coordinates are written longitude first — the opposite of the "lat, long" order everyone says out loud. If you're hand-editing KML rather than converting, this catches almost everyone at least once.
Both open in Google Earth. Pick KML if you want a plain, editable text file; pick KMZ for a smaller, self-contained file that's easier to email. If you'd rather keep working with the data, the same tool also exports GeoJSON, Shapefile, GPX and more.
Google Earth uses a placemark's name for the on-screen label, so put the text you want to see in a column called name. Every other column shows up in the popup balloon when a placemark is clicked. Keep names short — long labels overlap badly when points are close together — and move detail into separate description columns instead.
A few hundred rows convert instantly. Several thousand still work, but Google Earth itself starts to slow when it has to draw tens of thousands of labelled placemarks at once. If your file is very large, consider splitting it by region or category into separate KML layers you can toggle independently, which is far more usable than one enormous layer.
If the output has fewer placemarks than your sheet had rows, the missing ones almost always had a blank, zero or non-numeric coordinate. Sort by the latitude column and check the top and bottom of the sheet — empty cells and stray text are usually clustered there.
Address lists and site coordinates are often sensitive. This conversion happens entirely in your browser — the spreadsheet is never uploaded to a server — so nothing leaves your computer. That's a real advantage over tools that require you to hand your data to a website.
Customer addresses, patient locations, archaeological sites, rare-species sightings and unreleased development plots all routinely end up in coordinate spreadsheets. Uploading them to an unknown server can breach a data-protection agreement or a client NDA — and once a file has been transmitted you have no way to unsend it. Local, in-browser conversion sidesteps the question entirely.
Drop the .xlsx into a spreadsheet-to-map converter, confirm which columns hold latitude and longitude, then export as KML or KMZ and open the file in Google Earth. No add-in or install is required, and a browser-based converter keeps the spreadsheet on your own machine.
At minimum a latitude column and a longitude column in decimal degrees. A column called 'name' becomes the placemark label in Google Earth, and any remaining columns appear as attributes in the popup balloon.
Coordinates of 0,0 place a point off the coast of West Africa — nicknamed Null Island. It means the latitude and longitude values were blank, zero or not recognised as numbers. Check that the correct columns are selected and that they are stored as numbers rather than text.
Google Earth Pro can import a delimited text file, but the wizard is fiddly and does not handle Excel files, mixed coordinate formats or projected coordinates well. Converting to KML first gives you a cleaner result and a file you can share.
Google Earth only reads WGS84 latitude and longitude, so projected metres must be reprojected first. Tell the converter which coordinate system the values are in — for example EPSG:32631 for UTM zone 31N — and it will convert them to lat/long during the export.
The conversion itself handles large files comfortably, but Google Earth becomes sluggish when drawing tens of thousands of labelled placemarks. For very large datasets, split the data into several themed layers you can switch on and off.
