He once partied lavishly with the likes of American talk-show host Oprah Winfrey and other international celebrities, but for the past four years Mandela has blown out the candles alone with his family.
This year the revered statesman, who has been hospitalised twice in as many years, will be at his rural childhood home in Qunu, in the Eastern Cape province, where he has moved "for good".
These days his foundation and other organisations use his life example to encourage others to do good.
In 2009 the United Nations declared July 18 International Mandela Day, aimed to get people all over the world to volunteer for good causes.
The Nelson Mandela Centre of Memory, the charitable organisation which he founded after he stepped down from office, calls on people to devote 67 minutes of their time to charity work.
The number 67 represents each year of Mandela's life in active politics.
Andrew Mlangeni, an anti-apartheid activist who was imprisoned with him on Robben Island, said striving to emulate his values would be the best tribute.
"Living up to the ideals that he sacrificed so much for would be the greatest gift South Africans today could give Mandela," the 86-year-old told AFP.
"I wish him long life and good health. His presence is a blessing to all us South Africans and the world," he added.
'As well as any 94-year-old'
In January 2011, Madiba set the nation on edge when he was hospitalised for two nights with a respiratory infection.
Another brief hospitalisation followed in February this year for treatment of a "long-standing abdominal complaint".
Only the president's office is allowed to give details of his hospital visits, making the subject of his health a matter a select few know about.
He was last seen looking frail in a rare television appearance on May 30 to receive a symbolic flame marking the centenary of his party, the ANC.
Mandela's long-time secretary Zelda la Grange last week said he was in good shape.
"He is 94, so he is as well as any 94-year-old," La Grange told 5FM.
"He is healthy, he is well taken care of by family and the medical staff around him."
Last week, President Jacob Zuma described him as being in "good health" after a home visit to Mandela in Qunu ahead of his birthday.
South Africans across the nation will sing a special rendition of Happy Birthday at 08:00 on Wednesday, in an attempt by a Johannesburg-based civil society group to set a world record of the most people singing the rhyme at the same time.
"We aim to get 20 million people to sing Happy Birthday Madiba at 08:00 on Wednesday," said Yusuf Abramjee, the spokesperson of Lead SA.
"Schoolchildren will join in, and we encourage everyone, wherever they are to take a moment and sing for Madiba at 08:00," Abramjee told AFP.
In Qunu the Nelson Mandela museum is holding youth artist upliftment projects. In nearby Mvezo, where he was born, family head Chief Mandla Mandela will hand over books to local schools.