The climb factor is the percentage of your energy spent in climbing, which can be calculated using a method validated by real-world data from treadmills and trail races. The traditional elevation gain is a nearly useless figure.
This app estimates your energy expenditure and CF from running or walking, based on a GPS track or a track generated by an application such as google maps or onthegomap.
If you don't have a file handy, but want to try the software, right-click on this link to download the file sample.kml, then upload it using the form below.
After you click the submit button, it may take a little time for the results to be displayed. This will happen if the elevation profile for your route is not included in your input file, and therefore has to be downloaded from a database.
The model used to calculate the results is described in this paper: B. Crowell, "From treadmill to trails: predicting performance of runners," https://www.biorxiv.org/content/10.1101/2021.04.03.438339v3, doi: 10.1101/2021.04.03.438339
For a shorter and more nontechnical description, see this blog post: What’s the climb factor of your run?.
What it's good for:
This software is open source, and if you prefer to run it on your machine rather than through a web interface, you can do that from the unix command line.