Depending on your size, I think anyone who is over 8" BPEL in actuality is probably best to just say they are 8". Reason being is 8" even in girlspeak is still 'big', and if anything, they will likely think it is even bigger when they see it in person. If you were to round up and say 9-10", then there is the potential they will expect more than you are bringing to the table.
Honestly if pressured these days I'd just say 'somewhat over 7 inches', to 'close to 8'. I doubt anyone would turn things down due to thinking those are small, and they'd likely still be surprised if they saw it in person. Granted part of me would want to say 'about 6 inches...soft' just to see their reaction (and is technically still a truth in my case lol).