Time & Date
Age Calculator
This age calculator gives your exact age using a birth date and an as-of date. It returns years, months, days, total days lived, and time until the next birthday.
Quick answer
Age is calculated with calendar-accurate year/month/day differences.
What this tells you
- •Age is calculated with calendar-accurate year/month/day differences.
- •Total days is the exact day difference between birth date and as-of date.
- •Next birthday countdown is measured in days from the as-of date.
How to Use
- 1Enter date of birth.
- 2Enter the as-of date (defaults to today).
- 3Calculate to view full age breakdown and additional stats.
How It Works
Formula
Age = calendar difference between birth date and as-of dateThe calculator uses calendar arithmetic to compute full years first, then months and remaining days.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Age on a target date
Date of birth2000-01-01
As-of date2026-05-07
Result26 years, 4 months, 6 days
Common mistakes
- Using a future birth date
- Confusing current date and as-of date
- Expecting month counts to be fixed 30-day blocks
Frequently Asked Questions
Yes. Use any as-of date after the birth date.
Yes. Date calculations use real calendar dates.
It is the number of days from the as-of date until the next birthday.