Wattage Europe - USA/Canada etc?!?!?

Dont know if this a good place to ask, will probably ask on yahoo answer or summat but.....Ok i've noticed while browsing the forums that most States etc bulbs are a higher wattage for the same light. Here in the UK 100w equiv bulbs are around 18-20 watts at a voltage of 230-240v. Where on the other side if the pond i see 26w?(100w) at 120v.

Question is 20w/240v the equiv of a 26w/120v? or summat like that..... Anyone?

its okay i figured it out. a 100w incandescent bulb running on 120v produces more lumens than one on a 240v....