text: Interesting question Pharos91. \n\nOn the face of it you could just pick and age like 70, 80, 90, etc. But it isn't quite as simple as that. The majority of people die when they are old but few actually die of old age. Most die of an illness or disease of some description and that is not the same as dying of old age. \n\nAs an example. My two grandmothers both died at an old age. One had suffered a heart condition for thirty years and finally died age 96. She died as the result of a heart attack. The other simply went to sleep one night and never woke up again. She was 101. There was no evidence of any medical condition, her organism had nothing left to give and merely  quit working. She died of old age.\n\nSo, in answer to your question. A person dies of old age when the body has used up all of its resources and the organism ceases to function of its own accord. And since that will depend on what resources there were to start with, you can't simply apply a label like 70, 80 or 90.