Welshman Calzaghe is unbeaten in 44 fights
Joe Calzaghe says he will "retire and never show my face in public again" if he loses to Bernard Hopkins in Las Vegas on 19 April.
Calzaghe, 36, added that he was punching harder than ever ahead of his light-heavyweight debut and he plans to become the first man to stop Hopkins.
Super-middleweight king Calzaghe told BBC Sport: "I throw more punches and land more punches.
"That's what it comes down to, that's the basics of boxing."
Calzaghe, who is also making his debut on American soil, added: "I've definitely noticed that I'm punching harder in the gym. I will use the speed, but I'll definitely mix things up with the power punches, I want to knock him out.
"I hope he's got the Jeff Lacy (who Calzaghe outpointed in 2006) mentality and thinks that I slap, that I don't hit hard.
"Because he's in for a big shock. Believe me he's going to be feeling the power. I'm aiming to sit a bit more on my punches to hurt him."
Calzaghe, who is unbeaten in 44 fights, added that he believes he will be more effective at 175lb than he was at 168lb and that he has not diverged from his usual pre-fight training regime.
Let him carry on and keep barking and barking because on fight-night I'm going to be the bad guy
"I've not changed anything. The only difference is I'm not starving myself as much to make 12st," said the Newbridge man.
"I honestly believe making 12st drains my punching power. I've always been a big puncher, but over the last few years losing those last few pounds has made me struggle.
"Until you actually fight you don't really know how things will go, but as far as I'm concerned, I'll be better at the weight, much better. I'll have the punching power and the speed will be the same, the speed's always there."
Hopkins, who reigned as world middleweight champion for 10 years and who has lost just four of his 54 fights, has made much of his record against southpaws in the build-up to the fight.
The Philadelphian has recorded wins over Antonio Tarver and Winky Wright in his last two fights, both former world champions and both left-handers.
But Calzaghe said: "I know he's beaten quite a few southpaws, but I'm a totally different southpaw to anyone he's fought before.
"He's beaten eight or nine southpaws, but I've beaten 37 right-handers. So that must mean I'm better against right-handers than he is against lefties.
"And I'm no Winky Wright, who's a blown-up light-middleweight and went into his shell, and I'm not Antonio Tarver.
"I couldn't care less if he knocked them all out in the first round because things are going to be totally different when he steps in the ring with me."
Calzaghe also made assurances that Hopkins's trash-talking would not put him off his game in the lead-up to the fight.
"I think he tries to get into opponents' heads. But believe me, he's barking up the wrong tree with me," said Calzaghe.
"The loud one in the room is not the one you want to worry about. It's the ones who are quiet that I get worried about.
"He brings nothing in the ring or outside the ring that I haven't seen before. So I'll let him carry on and keep barking and barking because on fight-night I'm going to be the bad guy, I promise that."