Chronological Age Calculator in Years, Months and Days
Enter a date of birth and a reference date below to get age broken out in every format at once: years/months/days, total months, and compact Y;M;D, with no separate conversion step required.
Every Format at Once
- Years, months, days: the standard format required by most assessment publishers, for example, 7 years, 3 months, 14 days.
- Y;M;D: the compact clinical notation (7;3;14) used in Pearson manuals and Q-global scoring.
- Total months: a single number, useful for BRIGANCE Data Sheet selection, ASQ form selection, and quick conversions like “a 3-year-old is 36 months.”
- Total days: useful for research documentation and very young infants.
Can I get age in years and months only, without days?
Read just the first two units from the Years, Months, Days row. The full breakdown is shown, but you can use only the part you need.
Is this a different calculator from your other tools?
Yes. This is the only one that displays all four formats side by side in a single table. For a purpose-built version, see our Pearson or BRIGANCE calculators.