Question

If i was born in 1983 how old would i be?

Answer 1

Either 32 or 33 years old depending on the exact date.

Answer 2

Take the current year and subtract is from the initial year, so
This year is 2016, your are trying to find age if born in 1983
             2016
           - 1983
         -------------
                  33
You would be 33 years old if you were born in 1983 as of 2016.