Age Calculator
Calculate exact age in years, months and days from a date of birth.
How to use
- Pick the date of birth.
- Optionally change the “as of” date to calculate age on any day (past or future).
- Read the exact age in years, months and days - plus totals and next-birthday countdown.
Frequently asked questions
How is age in years/months/days calculated?
Calendar-accurate: years advance on each birthday, months on each month-day, and leap years are handled automatically.
Can I calculate age on a specific date?
Yes - set the “Age as of” field to any date, such as an exam cutoff or a form's reference date.
Exact age in years, months and days
'How old are you?' has a fuzzy answer; forms, applications and eligibility rules want a precise one. Enter a date of birth and this calculator returns age as of today - or any date you choose - in years, months and days, plus total months, weeks, days and even hours. That 'as of any date' option matters more than it looks: school cut-offs, visa rules, competitive exams and pension eligibility all measure age on a specific date, not today.
How calendar age is computed
Age here is calendar-accurate rather than a divide-by-365 approximation: it counts complete years first, then complete months, then leftover days, respecting the actual lengths of the months involved and leap years along the way. Someone born 29 February gets the conventional treatment - their age ticks over on 1 March in non-leap years. This matches how ages are computed legally and administratively in most of the world.
More than birthdays
The same calculation answers a family of everyday questions: how old is my car, my mortgage, my dog (in real years - multiply for dog years yourself); exactly how long until retirement; what's my baby's age in weeks for the paediatric chart; how many days until a wedding. For the gap between any two arbitrary dates - project durations, notice periods, interest day-counts - our Date Difference Calculator is the general-purpose version of this tool.