• Baptism, christening, or confirmation records.
• Census records which give your ancestor's age at the time of the Census.
• Your ancestor's marriage record that lists the age of your ancestor at the time of the marriage.
• Your ancestor's death, cemetery, or tombstone records.
• Your ancestor's obituary.
• Your ancestor's school records.
• Your ancestor's place in the birth order of a sibling for whom you know the age.
• The will of one of your ancestor's parents that lists the age of your ancestor at the time of their parent's death.
• Other court and probate records that require a declaration of age.
• Military and Pension Records may contain age information.
• Immigration, Naturalization, and Citizenship Records
• Family records and memorabilia like Family Bibles, old letters, birth announcements, or old photos.

When viewing baptismal records, if the dates are listed in chronological order, look for a pattern of multiple children baptized on the same date or a pattern of dates that fall seven days apart. This would suggest that the baptisms were not done within a few days after the birth but might be years from the birth date. Still an entry of the baptismal date for the birth date with the tag "BEFORE" would be appropriate and helpful.

Confirmations or first communions occurred at about age thirteen or fourteen. For children who died before the 1850 census, a confirmation record may be a good record for approximating the birth year. Always include in your notes that a date has been estimated and what source was used to make the estimation.

Census Records
Most genealogists are aware that the 1850 census was the first Census enumeration that included the age at the time of the census of each member of the household. Subtracting the age from the year of the census can give you an approximate birth year that is probably within 2 to 3 years of the actual. Be aware, when using the census records to estimate birth dates the validity of the information is directly related to the knowledge or memory of the individual giving the information. I will have to admit that as I get older I tend to get more forgetful of my own age and on occasion have misstated it. Also the census taker did not always get his information from the head of the house or from the wife. A neighbor, relative, or servant to the household may have given it. Using other sources to corroborate a Census birth date estimate would be a good plan. Even using another Census year could help to verify the birth year. The 1900 census not only included the age at the time the census was taken, but als o the actual birth year and month.

Marriage Record
Estimates of birth years from marriage records are a little less precise and rely on numerous factors. Is this the individual's first marriage? Did the marriage occur before or after the 1900s? What was the legal age of consent in the state where the marriage took place? Did the bride or groom lie about their age on the marriage license? Based on the US statistical studies reported by the CDC a male would be on average 24-26 years old at the time of the marriage and the female 21-23 years old. This is for the years from 1940-1967. If you use the statistics for the ages of the first marriage only, the groom would be 24-25 and the bride 21-22.

In 1786 the average age of a first marriage for a woman was 20.5 years. By 1889 the average age of marriage for women had gone up to about 22. The average age of marriage for men at that time was 26. In the 1920's the average age of marriage for women went down to 21 years. In the 1990's, the average age of marriage for men is 26.7 and for women 24.5 years.

You can see from the these statistics that the average age of marriage has varied little but the average difference between the age of the woman and the age of the man has changed from 4 years difference in the years 1800-1900 to about 2 years difference in the 1900s. It should be noted for these statistics, that we are talking about first marriages. Using the CDC statistics again it can be seen that when remarriages are included in the calculations, the average age increases for both the man (28.7) and the woman (26.7). It is interesting to note that these are the same average ages for marriage as in 16th Century England.

When estimating a birth date for the US using a first marriage date, assume the groom to be about 25 and the bride to be about 21, if the marriage took place before 1900. From 1900 to 1940 the estimated age of the groom would be 24 and the bride 22. From 1940 to 1960 the estimate age of the groom would be 26 years, and the bride 23 years.

For Canada and Australia the average age of marriage currently is 25-26 years for the bride and 27-28 for the groom which is pretty close to that of the US. However, earlier in the 20th century in these countries the average age of marriage was much higher than in the US, being 24-25 years for the bride and 26-28 years for the groom.

One startling statistic that I came across in my research was that the average age of marriage in England has risen since the 1990s: it went from 26 years for the bride and 28 years for the groom, to 32 years for the bride and 35 years for the groom currently.

Be sure to obtain another source to verify the age that is given on a marriage record. Marriage records are often inaccurate and the grooms and brides may have deliberately lied about their age so they did not have to get a parental consent. Occasionally, one of the marriage applicants may have given his or her age as a few years younger than reality to hide the disparity in age between the two applicants.

Death, Cemetery, or Tombstone Records
To estimate a birth date from a death, cemetery, or tombstone record, it would be necessary for the record to actually give the birth year or indicate the age at death. Generally this doesn't present a problem as most records of this kind do include this information. Often the age at death is represented as three sets of digits separated by dashes. For instance, 25-3-4 would represent the age at death as being 25 days, 3 months, and 4 years. The MyTrees.com website has a date converter to help you make the conversion to an actual birth date. Click here to access the date converter.

You will see some death records that do not give the age at death or will give a designation "infant". The term "infant" usually indicated that the child was below the age of 2 years. The term "infant" used in a legal document indicates a child of less than 12 or 14 years.

Obituaries
Though not my first choice for estimating a birth date, obituaries often do have a wealth of information to help you find a better record for estimating the birth date. Most obituaries give the name of the deceased, the date of death, an estimated age at death, and the place of residence at death. If the death was untimely from a sickness, accident, or violence, there would probably be more detail given and perhaps the ages of other members of the family would be included. Remember, the report of an event date is more accurate when given at a time closer to the occurrence of the event. For this reason, to trust the age information or birth information on a death record or obituary without getting another record closer to the birth event to confirm it is unwise.

School Records
Prior to the 20th Century most primary schools did not keep a comprehensive record of their students, except in the case of private preparatory and boarding schools, whose students were from wealthy families. When their records can be found, they usually included the name of the child, their grade level, and their age from which you could estimate their year of birth. Universities and colleges, however, kept much more detailed records of their students including the age at which they graduated and often a biography.

Birth Order
If you know the birth order of the children in a given family, you can estimate the year in which each was born by using the marriage date of the parents if the marriage was prior to 1961. The year of birth for the first child will be approximately the year following the year of marriage. Add two years to the year following the marriage for the second child, and then 2 years for each child after that. Generally the couple would have a child every two years unless the couple was apart due to his service in the military or other circumstances. Be particularly mindful of stillborn children that may throw this formula off slightly. This formula for calculating birth dates from birth order would not be valid after 1961, because the FDA approval of the birth control pill in May of 1960 changed the timing and number of children in many families.

Wills, Court, and Probate Records
Wills don't often have ages in them unless there was an under aged child that had to be accommodated. For instance, children that were under the age of consent might have been apprenticed usually to an uncle or brother or they might have been put in a foundling home. In that case the age will be given. Other court and probate records are much more valuable sources for finding the age of an individual at a given time. Since many legal actions required a declaration of age, a part of the court document would include the age of the individual at the time of the court action. From this you could estimate a birth year.

Military and Pension Records Military records will contain the age of the applicant when they enlisted and in most cases will be a good source -- if the applicant did not lie about his age in order to enlist. You'd be surprised how often this occurs. Pension records are much more valuable in establishing birth dates. Often a pension record will contain the birth dates of all the children and the wife, too.

Immigration, Naturalization, and Citizenship Records
These records will usually contain the age of the person at the time of the event. I am including ship's Passenger Lists in this category which also will contain the age of the individual, often the place of birth, and sometimes other relationship information too.

Family Bibles, Letters, and Photos
Family Bible records can be very accurate with regard to the recording of birth dates, especially if the entries were made at the time of the event. Of course it would be ideal if you could find a formal birth announcement among the family memorabilia. Even a photograph with an age on the back and the photo developing date printed in the margin would be a real find. Letters and postcards with the latest family news can provide written evidence to lead to an estimation of a birth year for an ancestor or two.

Conclusion
When you do not know the birth date of an ancestor, it is a helpful practice to estimate that date. There are a number of reasons for doing this. An estimation can perhaps reveal some unsuspected problem in the assignment of children to a family. For instance, it may indicate that perhaps not all the children of a man could have been born to his only known wife. The estimation can also help us to narrow the years within which future research might be conducted.

Although some of the dates estimated will in the future be found to be wrong, I believe that providing at least a time frame for our research helps us to more effectively use our time in our genealogical investigations.

Many of the extracted marriage records at MyTrees.com include estimated birth dates. These birth dates were estimated using some of the methods described above. To see the listings of the records, go to the MyTrees.com homepage and click the region for which you would like to see extracted records.