First off, the average lifespan figure is very deceiving. It includes all deaths, including infants, young children, and others that pass away before their time. As you get older, the average lifespan increases. There is a tool on the Social Security Administration website that you can use to see the life expectancy for a person of any age.
If you utilize this calculator, you find that the life expectancy for a man that is turning 67 today is 85, and for a woman it is 87. Of course, these numbers go up as the age rises. The life expectancy for a 70 year old woman is 88 years.