battery nominal capacity vs usable/ effective

[ggx]

ceteris paribus what is the diference in real range for ex Bosh 500wh vs 625wh battery?
Supose the diff. isn´t linear and the 625 has more usable "juicy" .
Any idea/maths out there?

 

[Russell]

Who knows, I get 18-20 miles in turbo out of my 500 battery and yesterday I did 33 miles using all of my battery and 3 bars of my wife's battery( so 2 bars left).