Bike and Rider Information:
Rider height (cm) (NB: not needed for CdA)
Rider weight (kg)
Rider frontal area (m3) (NB: not needed for CdA)
Bike weight (kg)
Drive train efficiency (%) (NB: 97.5% is typical)
Rolling resistance (Crr) (NB: look here for sample values)
Power meter type crank / pedal wheel
Sample Ride Information:
Careful selection of sample ride data is very important
Ride distance miles kms
Ride time (hh:mm:ss)
Ride average power (W)
Ride average grade (%)
Temperature (C)
Air pressure (mb)
Air density (kg/m3) 1.227
For more information and guidance on how to achieve the most accurate results, I strongly recommend reading the excellent published work of Dr Robert Chung who has pioneered this method of estimating CdA with a power meter (the "Chung Method"):
  Bike Aero Data - Nic Pillinger 2015