CraigyBabyJ guide
Calculate exact age in years, months and days
Exact age is awkward to calculate by hand because months have different lengths and leap years get in the way.
Use calendar units
A proper age calculation counts complete years and months instead of assuming every month is 30 days.
Check the reference date
For forms, birthdays or eligibility checks, make sure the calculation is using the right date, not just today's date by accident.
Use total days for exact gaps
Years and months are easier to read, but total days is the cleanest number when you need an exact gap.
Useful tools for this job
Use these tools when you are ready to try the workflow on your own files.