Write down your birthday in numbers, using the day first, the month next and then the year. For instance, a person born Jan. 16, 1982, would write 16+1+1982.
Add the numbers in the day part of the formula. For example, 16+1+1982 would turn into 7+1+1982.
Add the number for the day and the number of the month together. For example, 7+1+1982 would turn into 8+1982.
Add the numbers in the formula together. For example, the numbers 8+1982, becomes 8+1+9+8+2= 28.
Add any remaining numbers together to get one number. For example, 28 would be 2+8=10, then 1+0= 1.