Age calculator
Age as it is actually counted — years, then remaining months, then remaining days — rather than a decimal that means nothing.
Why age is not just days divided by 365
Age counts completed calendar years, so it increments on your birthday rather than accumulating smoothly. The months and days that follow are the remainder since that birthday, which is why the day count depends on how long the intervening months actually were. Dividing total days by 365.25 gets close but produces something nobody uses in conversation.
Leave the second field empty to use today, or fill it in to find someone's age on a specific date — useful for eligibility cut-offs, school year placement, or checking an age as of a past event.
The birth weekday is a genuine calculation from the calendar rather than a lookup, so it works for any date, and the next-birthday countdown accounts for whether this year's has already passed.
Questions
Can I check age on a past or future date?
Yes — fill in the second field. Leaving it empty uses today's date.
How are leap-day birthdays handled?
Someone born on 29 February has a birthday only in leap years. In other years the calculation rolls to 1 March, which matches how most jurisdictions treat it for legal purposes.
Why do the months and days look uneven?
Because months differ in length. The remainder after whole months is measured against the actual calendar, not an average month.