You have not provided sufficient data to give a meaningful reply.
Is the person still alive?
If so, what date was the person born?
What geographic location?
What time?
And where are you, the asker, now?
If one had all that, one could tell you exactly how old the person is. Otherwise, vague approximations only.
It is 2010, January 8th, 9:51am Central Standard time as I write this. Perhaps the person was born on this exact date and time in 1981, right in my own town, and is still alive. If so, the person is exactly 29 years old.
But maybe that person was born just like all that, but in London, six hours ahead of me. It makes a difference.
A person born in 1973 would be 36 years old on his or her birthday in 2009.
A person born in October 1983 would be 25 years old.
A person born in 1958 will turn 58 in 2016.
It depends on what day that person was born. If someone was born on January 1st, 1977, they would be 33 years old today (March 28, 2010). But say, for example, someone was born on September 1st, 1977... they would be 32 years old today.
That person will either be 25 or 26 depending on when their birthdays are.
2013 − 1981 = 32 years old.
About 29 years old.
As of October 2011, someone born in November 1981 would be 29 years old - turning 30 next month.
Subtract 2013 - 32 = 1981. If they turn 32 years old in 2013, they were "zero years old" (i.e., born) in the year 1981.
If someone was born in 1950, they would be 71 years old in 2021.
A person born in 1973 would be 36 years old on his or her birthday in 2009.
In 2014, if a person is 64 years old, then he was born in 1950.
87
1st birthday 1982 6th 1987 36th 2017
If I were born in April 1981, I would be 40 years old.
Since the oldest person at the time was somewhere near 110 years old you "was" born anytime from 1871 to 1981. Rather open ended question...
If you are born on 1981-2011 you are 30 years old