Date & time
Date difference
Count calendar days and weeks between two dates.
Calculators / Date & time / Age
Age calculator
Calculate exact calendar age plus total months, weeks, days, the next birthday, and birth weekday.
On this page
Completed years36years
Exact calendar age36 years, 8 months, 6 days
Total completed months440months
Total completed weeks1,914weeks
Total days13,398days
Next birthday2027-01-01
Days until next birthday116days
Born on aMonday
Calculator controls
How to calculate
Calculate exact calendar age plus total months, weeks, days, the next birthday, and birth weekday.
Calendar age is found by subtracting complete years, then complete months, then remaining days. Totals use the exact UTC calendar-day interval.
Worked example
Date of birth: 1990-01-01; Age on date: 2026-09-07.
Completed years: 36 years; Exact calendar age: 36 years, 8 months, 6 days ; Total completed months: 440 months; Total completed weeks: 1,914 weeks; Total days: 13,398 days; Next birthday: 2027-01-01 ; Days until next birthday: 116 days; Born on a: Monday .
Assumptions and limits
Uses Gregorian calendar dates. A February 29 birthday is observed on March 1 in non-leap years for the next-birthday calculation. This is not a legal age determination.
Results are rounded for display; calculations use unrounded values. Read our calculation methodology.
Understanding the result
Completed years count full birthdays reached by the selected date. Total days reports the calendar interval since birth.
When this tool is useful
Check age on a specific past or future date.
Understanding your inputs
| Input | What to enter |
|---|---|
| Date of birth | Enter the value in the format shown. |
| Age on date | Enter the value in the format shown. |
Frequently asked questions
What does completed years mean?
It counts full years, not a decimal approximation obtained by dividing days by 365.
Can this establish a legal age deadline?
No. Rules for leap-day birthdays, time zones and legal deadlines can vary. Check the applicable rule for that purpose.