Age Calculator
Enter a date of birth and this age calculator shows the exact age in years, months and days — plus total months, weeks and days, and how long until the next birthday. Leave the second date empty to use today, or set any 'as of' date to find age on that day.
Last updated:
Calculate age
Enter values above and press Calculate to see your result.
Formula used
Age is the full calendar difference: count whole years, then months, then days, borrowing from the previous month where needed.
Total days = (as-of date − birth date)
Worked examples
Born 15 Jun 1990, as of 13 Jun 2026: 35 years, 11 months, 29 days.
Total days ≈ 13,147 — useful for milestone counts like 10,000 days.
How to use this calculator
- Enter the date of birth.
- Optionally set an 'as of' date (defaults to today).
- Press Calculate.
- Read the exact age plus total months, weeks and days.
How age is calculated
The calculator subtracts the birth date from the target date, counting complete years first, then remaining months, then days — borrowing days from the previous month when the day-of-month is smaller. This matches how age is stated in everyday life and on official forms.
Uses for an age calculator
- Exact age for forms, eligibility and contracts.
- Age gap between two people (use one birth date and the other as the 'as of' date).
- Milestone days — 10,000 days, 1,000 weeks, etc.
- Days until the next birthday.
Frequently asked questions
How do I find age between two dates?
Enter the earlier date as the date of birth and the later date as the 'as of' date. The result is the exact difference.
Does it count leap years?
Yes. The day total uses actual calendar dates, so leap days are included automatically.
Can I find a future age?
Set the 'as of' date to a future date to see how old someone will be then.