Getting started
Quick start: your first CdA estimate in 10 minutes
Set up your rider profile, add a bike, import a ride and see your first numbers.
1. Fill in the Rider tab
Enter weight, height, inseam and build. These carry over as defaults to every bike's fit model, so you only enter them once. FTP is optional but unlocks W/kg.
2. Add your bike
On the Bikes tab, pick your frame from the catalog so WattGap starts from its published wind-tunnel figure. Choose your frame size, tires, rim widths and cockpit (spacers, stem, bar width).
3. Import rides
Upload .FIT, .GPX or .TCX files from Garmin, Wahoo or any head unit on the Import tab. Files are read in your browser; only ride summaries are saved.
4. Compare
Use Calculator to see speed at a given power, and Time Delta to see how many seconds a setup change saves over a distance.
Try it on your own rides
Start free →