Estimate a birth date from a known death date and age at death — useful in genealogy research where only a death record and stated age survive.
How it works
The estimate is death date − age at death (years), keeping the same calendar day and month. Someone who died on 2020-06-15 at age 80 was likely born around 1940-06-15.
What this does not include
This gives an approximation, not an exact date. The true birth date could fall anywhere within about a year of this estimate, depending on whether death occurred before or after that year’s birthday — genealogical records (birth certificates, census data) are needed to pin down the exact date.
How to use this calculator
- Enter the date of death.
- Enter the age at death.
Why isn’t this estimate exact?
“Age at death” only tells you a completed number of years, not the exact day — someone who died a month before their birthday and someone who died a month after both might be recorded as the same age, but were born up to a year apart.
Is this useful for genealogy research?
Yes — it’s a common first step when only a death record with a stated age survives, giving a starting point for narrowing down birth records to search.
How would I get a more precise birth date?
Cross-referencing census records, birth certificates, or other documents that state an exact birth date, rather than relying on an age-at-death approximation alone.
