Kettlebell Kettlebell press to double press

[Anatoly]

Does anyone know the ratio of kettlebell presses and cleans to double presses and cleans? Ive heard everything from 0.67-0.9

 

[Maine-ah KB]

for me I can press the 40kg for a single and I have pressed a pair of 36kg (though it was a GRINDER) so for me. depending on how you set up the ratio 40/(2x36kg)=0.56 or my one arm press if 56% of my one arm press. I don't see how someone could do 90% of your double press with one arm (unless there very new to doubles).
How are you setting up your ratio? one arm press/total of double press? weight of one side of your double press/one arm press?