Google lists it as a 20 minute walk, which is consistent with the last time I did it. https://www.google.com/maps/dir/San+Francisco+Caltrain+Station/37.7856394,

Google lists it as a 20 minute walk, which is consistent with the last time I did it. https://www.google.com/maps/dir/San+Francisco+Caltrain+Station/37.7856394,-122.4056854/@37.7735179,-122.4055305,15z/data=!4m9!4m8!1m5!1m1!1s0x808f7fd6eb33becf:0xb7d880249f5a29f9!2m2!1d-122.394323!2d37.776439!1m0!3e2 https://www.google.com/maps/dir/San+Francisco+Caltrain+Stati... I'd say adding 20 minutes each way to your commute is a pretty big deal.