Questions about font size is what brought me to mobileread.
The comparison charts may list the number of fonts, and number of sizes but rarely the sizes....
This image seems to be the new 8 sizes for the kindle, and kindle dx
My reader the jetbook lite had no mention (at time of purchase) of what the six font sizes were but the device lists them as; 12, 16, 18, 20, 24, 32
I can usually read at the 24 pt size, but like having the availability of the 32 pt size for lower light, reading while walking using the auto page turn........