Genealogy – Age at Death

Ever needed to convert age at death to date of birth? Here is a way to do this.

REMEMBER 8870

That’s not an error. It’s the number to remember when you want to find the birthdate of someone and you have only the death date and age. How do you figure the birthdate?

Let’s suppose that the person died May 6, 1889, at the age of 71 years, 7 months, and 9 days.

  • Write death year, month, day as 18890506
  • Subtract the age at death: 710709
  • This gives the figure 18179797
  • Now subtract 8870

The result is 18170927 Birthdate is 1817, 9th month (September), 27th day, or 27 September 1817.