AgeCalc · English
Date of Birth Calculator from Age
When a record gives only a person's completed age on a known date, their exact birthday is unknown. This calculator returns the earliest and latest possible birth dates consistent with that information.
Enter the recorded age
Your entries are used only to produce the response, are not stored, and the result page is not cached.
Why age produces a date range
A person recorded as age 30 on 15 September 2026 may have been born from 16 September 1995 through 15 September 1996. Someone born earlier would already be 31; someone born later would still be 29.
Use the result to narrow a search in census, genealogy or administrative records. Do not treat either endpoint as the person's confirmed birthday without another source.
Calendar-year subtraction is not enough
Subtracting 30 from 2026 gives two candidate years but does not settle the month and day. The reference date and whether the birthday has occurred define the interval.
The calculator uses completed Gregorian years. Historical records may use stated age, age at next birthday or another convention, so check how the source recorded age.
Frequently asked questions
Can this recover an exact date of birth?
No. Completed age alone normally identifies a one-year inclusive range.
Are both endpoint dates possible?
Yes. The earliest and latest dates are included under the completed-age convention.
Can I use an age recorded at death?
Yes when the record states completed age and the reference date is the date at which that age applied. Check the record's convention first.