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Calculate age
Calculate exact age on today’s date or another date.
Exact age
Age–
Months after birthday–
Extra days–
Total days lived–
ⓘCalculations run locally in your browser. ToolCetra does not store the values you enter.
Calculate an exact calendar age
Enter a date of birth and an end date to calculate age in completed years, months and days. The result also provides useful totals such as days lived and time until the next birthday.
Why exact age is not just days divided by 365
Calendar years and months have different lengths, and leap years add an extra day. An exact age calculation follows calendar boundaries rather than using an average year length.
Common uses
- Checking age on a specific date
- Calculating time until a birthday
- Completing age-based forms or applications
- Comparing the ages of two people
Frequently asked questions
Which end date should I use?
Use today for current age, or select another date to find age at a past or future point.
How are leap-day birthdays handled?
The calculator follows calendar date arithmetic. Legal treatment of a 29 February birthday can vary by jurisdiction.
Can I calculate only the gap between two dates?
Yes. The Date Difference Calculator is designed for general date intervals.