For those who are willing to reave their soul into pieces, virtually forever. See, for example, the infamous dark wizard Lord Voldemort. Normally, wizards and witches live slightly longer than the average muggle. A lot died during the wars, but on average a wizard or witch could survive up to 90 yrs. This is more likely due to these people being among the more gifted part of the population than any special magic. Albus Dumbledore survived up to 115 or 116 until he died in sacrifice for another, but he was an exceptionally gifted and long-lived individual. Possibly, very powerful wizards live longer than muggles due to the powerful magic inherent in their blood. For wizards in the medieval times, they lived for about the same time as contemporary muggles, as long as they weren't burnt at a