Enter your date of birth to get your precise age in years, months and days, the total days you've lived, and a countdown to your next birthday.
How to use this calculator
Enter your date of birth with the date picker.
Read your exact age in completed years, months and days, plus the total days you have lived.
Check the countdown to your next birthday below the main result.
Use Share to send a link that reopens the calculator with the same date.
Formula & method
How exact age is computed
Age = today − date of birth, in completed years, months and days
Days are borrowed from the previous month's length and months from the year when needed, so the result is calendar-exact — the same way ages are counted legally. Total days use the real day count including leap years.
Example
Someone born on 1990-01-01 is, on 2026-06-01, exactly 36 years, 5 months and 0 days old — 13,300 days in total.
Key insights
Age in completed years is the legal convention: you turn 30 on the 30th anniversary of your birth date, not a day earlier.
A year of life is about 52 weeks or 8,766 hours; the 10,000-day milestone lands around age 27 and a half.
Leap years are counted exactly in the total-days figure — someone born in 1990 has lived through nine February 29ths by 2026.
Months vary from 28 to 31 days, so the 'months and days' part follows the real calendar, not a fixed 30-day month.
How to interpret your result
Two views of one duration
Years/months/days is the calendar breakdown; total days is the exact count. Both describe the same span — use whichever fits your need.
Day-count milestones
The total-days figure reveals milestones the year count hides, like your 1,000th, 10,000th or 20,000th day.
Next birthday
Counted from today to the next occurrence of your birth month and day, handling leap years exactly — 'in 0 days' means it is today.
Frequently asked questions
How are leap years handled?
The total-days figure is an exact calendar difference, so every February 29 in between is counted. The years/months/days breakdown follows real month lengths.
Why do months have different values in age calculations?
Because months differ in length (28–31 days), age in months/days depends on the actual calendar months crossed, not a fixed 30-day month.
Can I calculate age at a past or future date?
This version compares against today. Age at a custom reference date is on our roadmap as a date-difference calculator.
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