Elapsed days
total days = target date - birth date
General tool
Age Calculator
Find exact age in years, months, days, total days, weeks, and time until the next birthday.
Calculator
Enter values
Results update automatically as soon as enough values are available.
Result
About this calculator
How it works
Age is the elapsed calendar time between a birth date or start date and a target date. This age calculator uses calendar years, months, and days, so it handles different month lengths and leap years more naturally than a simple day-count division.
Formulas
Formulas used
Calendar age
Subtract years, months, and days, then borrow from the previous month when the target day is earlier than the birth day.
Next birthday
next birthday = next occurrence of the birth month and day after the target date
Worked example
Example calculation
Exact age
Born 2000-01-15 and checked on 2026-05-06 gives 26 years, 3 months, 21 days
Total days
The same dates are also shown as total elapsed days and approximate weeks
Guide
How to use this calculator
- Enter the birth date or starting date.
- Enter the date you want to calculate age at, or leave it blank to use today.
- Read the calendar age first, then use total days, weeks, and months for alternate duration views.
- Use the next birthday result when planning milestones, eligibility dates, or reminders.
Reference
What the results mean
Calendar age
Age expressed in complete years, months, and days.
Total days
The exact elapsed day count between the start date and target date.
Total weeks
Elapsed days divided by seven, useful for quick duration checks.
Next birthday
How long remains until the next birthday after the target date.
Assumptions and limits
Before using the result
- The calendar age result counts complete years, months, and days.
- Leap years and different month lengths are handled using calendar dates.
- Legal, medical, school, insurance, or eligibility rules may define age cutoffs differently, so verify official requirements.
FAQ
Age Calculator questions
How do I calculate exact age from date of birth?
Enter the birth date and the target date. The calculator subtracts the dates as calendar years, months, and days, then also shows total elapsed days.
Can I calculate age on a future or past date?
Yes. Use the Age at date field to calculate age on any date after the birth date. Leaving it blank uses today.
Does the age calculator handle leap years?
Yes. It uses real calendar dates, so leap years and month lengths are included in the elapsed age calculation.
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