This isn't a question about any particular death certificate, but rather a general question. On modern birth certificates, say after 1950, the general style seems to be to give the date of death, the age in full years and then the date of birth. This seems quite logical.

However, on older death certificates, usually before 1900, the forms asked for the date of death and the age of the deceased in years, months and days. Why would this be done? Is there some benefit to this that I am not seeing?

Clearly, people in the 19th century did not wake up each morning telling their family "In case I die today, I am 79 years, 10 months and 8 days old." I assume that, like today, the relatives knew the birth date (or at least an approximation thereof), gave that to the town clerk and the clerk then manually calculated out the age for the certificate.

The obvious problem with this is that it introduces extra chances for error. In addition to a mis-remembered or misheard birth date, the clerk could make an error in arithmetic or when copying the answer over, and we as genealogists could make an error when re-computing the birth date (although I'm sure they weren't concerned with us at the time). And as I have found in my own research, arithmetic or transcription errors certainly occurred, as I have at least one death certificate from the transition period (about 1900-1950) where it asks for date of death, age in years months and days and date of birth, and the information is self-contradictory.

So given that making an error seems more likely with this practice, why was it done? Isn't the exact date of birth more important than the exact age? Or is that just a modern view?

It was pointed out to me in the comments that this might not have been a universal practice, so for clarity, I am from New England and most of my records are from New Hampshire and Massachusetts, with a smattering from Vermont and Rhode Island.

This is an example of the usual format, from NH, with the age in years/months/days and no birth date. The latest example of this style that I found from a quick scan through my images was from 1916.

enter image description here And this is an example of a self-contradictory death certificate. It gives the date of death as June 5, 1912, the age as 89 years, 9 months and 13 days and the date of birth as August 23, 1822. However, if you use an online calculator and subtract the age from the date of death, you get a birth date of September 23, 1822.

As to how these dates and ages were calculated, I'm not entirely sure. Today there are formulas such as this one that were used, but they may well have used a calendar. I don't honestly know. But I have over one hundred examples of death certificates and the vast majority give a calculated age, so I suspect they must have had a formula or method.

Of course, there is another potential wrinkle in all this. Suppose the deceased was born in New Hampshire in 1740 and died in 1820, living through the Julian to Gregorian switch. The clerk is given a birth date and calculates the age. He could calculate the right age. Or, the family could give him the Julian date and he could fail to account for the missing 11 days. Or they could give him a date that was already converted to Gregorian, but he could accidentally convert it a second time, putting his result off by three weeks.

As you can see, the potential pitfalls of doing this are nearly endless.

  • I just did a quick survey of the only four 19th century death certificates of my ancestors that I have at hand 1853 (South Australia), 1861 (Scotland), 1867 (Scotland) and 1884 (Scotland) and none have the age at death in years, months and days recorded. They merely have age at death in full years and the date of death, and none have the date of birth. I think you should include the date and jurisdiction of an example death certificate.
    – PolyGeo
    Jul 26, 2017 at 7:18
  • 2
    I think that I've seen this on US certificates. To be honest, I think that why they did it can only be answered by a personal opinion?? But there is a specific question - how did they calculate? How long are those months? Are they just counted as pages on the calendar, in which case forget about leap years?
    – AdrianB38
    Jul 26, 2017 at 9:36
  • Yes, I suppose I should clarify the question. I am from New England, so most of my records are from New Hampshire and Massachusetts, with a smattering from Vermont and Rhode Island. I'll see if I can add a picture to the question.
    – Jack
    Jul 26, 2017 at 11:24
  • It seems to me that doing this, calculating the age, especially before calculators, added a non-trivial amount of work. Thus I have to imagine that they had a good reason for doing so. Maybe to make it easier for the family to have the exact age added to the headstone? Because it was certainly common for old headstones to give at least the years and months of age. But that is a total guess.
    – Jack
    Jul 26, 2017 at 12:07
  • From what I've seen, it was often the case that the day of death wasn't included in the years-months-days total - a lot of calculated DOBs on FindAGrave are off by one because of this. Speaking of transcription errors, I found one case where the age and year of birth were apparently swapped, which isn't even self-contradictory - someone b.1863 who died age 69 and someone b.1869 who died age 63 still died in the same year.
    – cleaverkin
    Aug 1, 2017 at 18:58

1 Answer 1


Government records are created because of a law that passes, mandating that the records be created and kept. The reason why the law was created may be in the relevant statutes, or not. If not, you would have to see if the legislative body which passed the law has kept records of the debate for the legislative session during which the law was discussed.

Try a Google search for the 'statutes' and 'online' plus the name of the state to find the relevant law. Once you have established the time-frame, search for more information at the websites of that state's Secretary of State, the governing bodies, the State Archives, or the Law Libraries associated with universities in that states.

For a discussion of the New England Records, see this post from Vita Brevis: Calculating age at death – and why.

Nineteenth and twentieth century death records also recorded the age at death, but this practice was not just customary. Instead, these modern death records provided statistical information for the nation’s politicians and doctors, as well as for life insurance companies. For example, in a Report of the Vital Statistics of the United States, made to the Mutual Life Insurance Company of New York, the author reported that the average age at death of the residents of Plympton, Plymouth Colony, Massachusetts, between the years 1812 and 1842 was 40 years, 10 months, 25 15/24 days.

The article also includes links to calculators.

  • Ahh, that's a very interesting link. I had heard of the 8870 formula before and was trying to find it to include in my question as a possible means of calculating the age, but I couldn't remember what it was called.
    – Jack
    Jul 27, 2017 at 0:20

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