Total days
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Everyday · Dates
Age
Age
calculator
Your exact age in years, months and days — plus how many days you have lived and how long until your next birthday. Change the date and it recomputes instantly.
Exact age breakdown
local time
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In weeks
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Next birthday
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How your exact age is worked out
Your age is the time from your date of birth to a chosen date — by default, today. The natural way to express it is in whole years, then the leftover whole months, then the remaining days. Getting the leftovers right needs a little borrowing, exactly like subtraction on paper.
The method
Subtract day from day, month from month, year from year.
If days go negative, borrow the days in the previous month.
If months go negative, borrow 12 months from the year.
If days go negative, borrow the days in the previous month.
If months go negative, borrow 12 months from the year.
Why "total days" is different
Years and months are uneven — 28 to 31 days each, with leap years adding a day every four years. So "42 years, 3 months, 8 days" and a flat "total days" figure describe the same span two different ways. The calculator gives both, along with your age in whole weeks.
Leap years
The count works in real calendar dates, so every leap day you have lived through is already included in the totals — no need to adjust anything yourself.
Next birthday
The countdown finds your next birthday on or after the target date and counts the days to it. If today is your birthday, it says so. Curious about the gap between two specific dates instead? The date difference calculator handles any pair of dates.
Common questions
Age FAQ
Your age is the span from your date of birth to a target date, expressed as whole years, then leftover months, then leftover days. If the day count goes negative it borrows from the previous month, and if months go negative it borrows a year.
Count the calendar days from your date of birth to today. This calculator shows the total days and the equivalent in whole weeks, both updated as you type.
Yes. It works in real calendar dates, so every 29th of February you have lived through is already counted in the totals.
Yes. Set the "Age at date" field to any date and it measures age at that point — useful for working out how old someone was, or will be, on a given day.
The calculator finds the next occurrence of your birth date on or after the target date and counts the days remaining. On the day itself it shows a birthday note.