Germany reached the showpiece at the Maracana courtesy of a 7-1 demolition of a sorry Brazil in Belo Horizonte on Tuesday, while Argentina required a penalty shootout to see off the Netherlands in their semi-final.
And speaking in a press conference ahead of the squad's departure to Rio de Janeiro, Lahm claimed that Germany's greater know-how in big games will work in their favour.
"A lot of our players have experience of playing in big finals with big clubs," he said. "That's definitely an advantage for us.
"You never know how far you will go, but we've prepared well, worked as a team and now we're one step away.
"I'm looking forward to the final. We want simply to become world champion.
"[If we won] I would go to bed early...or maybe in the early hours."
Sunday's World Cup final is a repeat of the 1986 final, in which Argentina prevailed 3-2, and the final in Italy four years later which saw Germany take the crown with a 1-0 victory.