Free Birth Date Calculator with UK & US Census Dates

New version 1.51 with US census dates added.
Now available from

The images below show an example of use of the Birth Date Calculator.
To use you must Download or Run

Enter an event date (or select a UK census date) and a person's age on that date to calculate their range of possible birth dates. Click on the Date edit box down arrow to view a calendar for the month or show the weekday of the event date.

Date format (d-m-y or m-d-y etc.) will be copied from your Control Panel settings.
Earliest date accepted by the date input field is Sep 1752; this corresponds to the 
change from the Julian to the Gregorian calendar with the skipping of 10 days.

Let the mouse cursor hover over the entry fields and buttons for help.

Note that for the 1841 UK census all ages 15 and above should have been rounded down to the 
nearest 5 year multiple, i.e. ages shown as 15 may be 15-19, ages shown as 20 may be 20-24, etc.
So when 1841 census is selected and the age is a multiple of 5 (15 or over) a 5 year birth date range
is provided. (But entering this date manually in "Date of Event" gives the normal 1 year range.)

For Microsoft Windows only; developed using Visual C++ 2008. 
If you find any bugs or have suggestions for possible enhancements please let me know.

For all versions of Windows simply:

Download or Run : BirthDate.exe (V1.51 301 kB)        Version Info

Program is ready to use as downloaded and does not require further installation.  Easiest method of use
 is to select Save from download dialog and then select Desktop where a copy and  icon will appear. 
To update or remove simply delete existing file. (There are no registry entries, cookies or .dll files) 

Last modified 26 January 2018