GPX elevation profile

How to use it

Drag the file onto the tool or pick it with the button. A GPX from Strava, Garmin, Komoot, AllTrails or any other app works, and so does a simple KML from Google Earth or Google My Maps. It’s read in your browser: the file isn’t uploaded anywhere.

You’ll instantly see the track on the map, the profile, the route’s numbers and the grade section by section. Move your finger or mouse along the chart to see where each point is on the map. You can download the profile as an image to share, the data as CSV, or the route as a GPX with elevations.

Elevation from the file or from the terrain model

If the file includes elevations, you can switch between those and the terrain model. The file’s elevations are what your device measured: good with a barometric altimeter, quite noisy with GPS alone. The terrain model ones come from the Terrain Tiles, a worldwide digital elevation model published on Amazon Web Services that uses the best public data for each area, such as the USGS 3D Elevation Program in the United States and NASA’s SRTM elsewhere. They’re the same for every route, so they’re good for comparing one with another. To read them, your browser downloads the elevation tiles for the area; the route itself never leaves your device.

For a single point in Spain, the Elevation finder uses a finer model, the 5 m MDT05 from Spain’s National Geographic Institute. For profiles, with hundreds or thousands of points, we use the Terrain Tiles everywhere.

How the climb is worked out

Total climb adds up every uphill stretch, and total descent every downhill one. To avoid adding up noise, a change only counts once it passes a threshold: 3 m (about 10 ft) with the terrain model and 5 m (about 16 ft) with the file’s elevation, which is noisier. The average grade is all the climbing and descending divided by the distance, and the steepest grade is the largest over any 100 m (about 330 ft) stretch.

Why is the GPS climb higher?

GPS elevation shifts by a few meters from one second to the next, even on flat ground. Add up all those wiggles and, by the end of a long route, you get a lot of climbing you never did. That’s why raw GPS elevation gain usually comes out higher than the real one. The threshold removes much of that noise, and the terrain model doesn’t have it, though it can come up short on tight switchbacks or narrow ridges. If both numbers are close, that’s a good sign.

How the time is estimated

We use Naismith’s rule, the classic rule of thumb devised by the Scottish mountaineer William Naismith in 1892: allow 1 hour for every 5 km (about 3 miles) of distance, plus 1 hour for every 600 m (about 2,000 ft) of climb. Descents add no time.

It assumes reasonably fit walkers on good paths, with no breaks. With kids, a heavy pack, snow or rough ground, allow more.