I saw this on a "users group" site ... it might be useful to some of you .... "Unknown birth dates can be estimated by using known birth dates of other family members. This is the formula that professional genealogists use to estimate birth dates for when you don't know the birth date. . Precede estimated birth year with "Abt or Est" Estimate the father's birth year by: subtracting 26 years from birth year of first child. .... OR subtracting 4 years from birth year of wife .... OR by subtracting 25 years from marriage year. Estimate the mother's birth year by: subtracting 22 years from birth year of first child .... OR adding 4 years to birth year of husband ... OR by subtracting 21 years from marriage year Estimate birth year of other children by: adding 2 years to birth year of previous child If birth date of child is unknown: Add 25 years to birth year of father ... OR 22 years to birth year of mother." ************************* Thanks Dick Schweiss (List Admin. for) Brown County, MN Mail List ... [email protected] Researching surnames: SCHWEISS .. MEIER .. SCHMITT/SCHMIDT .. STADTHER(R) .. MEHLTRATER My Genealogy Site: http://www.harbornet.com/folks/dick/SchweissFamilyHistory.htm