User blog comment:Congo1/Noob Tips/@comment-75.151.77.218-20121114190027/@comment-5706972-20121114193749

Go to the attack screen (pick any opponent - it doesn't matter), and in the top right-hand corner it will tell you what your total attack is. NOTE: It will only tell you for how much attack you currently have - so you will need to look when your ATK power is full to get an accurate number. Also, if you don't have enough cards in your back line to use all of your attack power this number might be lower (ex: you have 300 ATK power, and only 5 cards in your deck - you will only use the portion of your ATK power required to activate the cards in your deck).