I’ve always wondered if the Strava estimated power was close to real power. So on a couple of specific segments I’ve run my phone using Strava and my Garmin using a power meter so that I can compare.

You can see from the screenshots below the differences.

In summary for smaller segments it was within 5%, drifing out to 13% on a 20 minute section, so you would assume it would drift further out for a full ride, something I will try in the near future. Interesting side note that the phone often gave me a second quicker time….

  Segment time Real Power Estimated Power Difference
Langbar Reverse 20:55 246 214 -13%
Roker Lane 02:30 367 356 -3%
Crekeld Lane 05:41 299 288 -4%

Langbar Reverse

lang_est lang_real

Roker Lane

roker_real roker_est

Creskeld Lane

creskeld_est creskeld_real