BrianG speed calculator question

Hey guys, when enter your lipo batterie voltage on the BrianG speed calculator, for exemple, a 3s li-po, did you enter 11.1 or 12.6????????????
I have always enter 11.1 before, but now, i think that i will put 12.6 volts, because the fully charge 3s pack is 12.6 volts and hold this voltage very long.........
Or for a more accuracy value, maybe 12 volts will be more realistic, no??