Hi Steve, not really my field but looking at the figures you posted, and assuming a 'halfway linear relationship' logic says you need an 11 x 6 prop!
If I were you I'd start Dave's experiments and sea trials with that. Good luck👍, Doug 😎

Thanks Dave. I'll give it a 'whizz'.

Steve

Hi Steve
Stick your motor on a temp ramp holder and connect up to the ESC.
Get a selection of different sized props and pitches and fit one to the motor.
Connect the battery via a Wattmeter and run the motor at full whack. Record the results Amps and watts.
If either are above the motor or ESC ratings the prop is too big or too coarse pitch...
Try with different props until you find one that is within ratings spec
This is a very rough and ready method and the load will reduce when the model is in motion so will always be within spec.

Once you have the size and pitch it really is a question of trying slightly different sizes and pitches to get the best for your model.

Take great care when testing with air props, modern brushless motors pack a big punch and at full whack any contact with the blade is to be avoided.
Dave