The 34-year-old former England captain "feels fine and is happy" as he recuperates from Monday's operation at a private clinic in Finland, his surgeon told The Associated Press. He added that Beckham would stay at the clinic until today.
"He does not have much pain and has started walking today and gradually done it more and more," Dr. Sakari Orava said.
Beckham was injured in the closing minutes of AC Milan's 1-0 win over Chievo Verona on Sunday. He was on his second loan to the Italian club from Major League Soccer's Los Angeles Galaxy.
"I'm feeling positive and now concentrating on getting back to full fitness over the coming months," Beckham said in a statement Tuesday.
Orava said Beckham's left Achilles' tendon was totally torn, ruling out his hopes of playing in his fourth World Cup. The tournament starts June 11 in South Africa.
"It is hard to tell, but in general I can say that after an Achilles' tendon tear, a total rupture, people usually are back in sports within half a year," Orava said.
AC Milan said Beckham would begin rehabilitation right away. He is not to put weight on his injured foot for two weeks and can undergo physical therapy in a pool after six weeks.
"The plan includes a complete recovery in six months, at the end of which he can play again," the club said in a statement.
Beckham's wife, Victoria Beckham, formerly known as "Posh Spice" of the Spice Girls, arrived by private jet Tuesday afternoon at a snowy Turku airport. She was taken to the clinic in a van with tinted windows.
Wearing a short black dress, sunglasses and no coat, she was met by dozens of screaming fans and photographers in the parking hall of the shopping mall. A policewoman and a security officer escorted her out of the car, fending off the pushing crowd as she hurriedly made her way to the elevator.
David Beckham is under contract to AC Milan until June 30.
"So all the eventual contractual obligations will continue to apply," Milan organizing director Umberto Gandini told the AP. "After June 30, he will become a Los Angeles Galaxy player again. From the contractual point of view, absolutely nothing changes."
Milan physicians followed Beckham to Finland and will also coordinate the first steps of rehabilitation.
"Until June 30 his rehab will be arranged in accordance with Milan and the Los Angeles Galaxy," Gandini said.
The injury shattered Beckham's hopes of becoming the first English player to appear in four World Cups and put his future on the national team in doubt.
He will miss most of the MLS season.