Age Calculator
Free age calculator: enter a date of birth to get exact age in years, months, and days - plus total days lived. Optional age-at date for past or future dates.
Defaults to today. Change it to find age on a past or future date.
26
Years
6
Months
29
Days
9,707
Total days
About Age Calculator
Find out exactly how old you are - or how old someone was on any date - with this free online age calculator. Enter a date of birth and optionally an "age at" date (defaults to today) to see chronological age in years, months, and days, plus the total number of days lived. All math runs in your browser with correct calendar month and day borrowing.
How to Use Age Calculator
- Enter the date of birth in the first field.
- Optionally set "Age at date" (defaults to today) to calculate age on a past or future date.
- Read years, months, days, and total days instantly in the result cards.
- Change either date to recalculate - no button or signup required.
Age Calculator Examples
Exact age today
Born January 15, 2000 and checking on July 30, 2026 → 26 years, 6 months, 15 days.
Age on a birthday
Born July 30, 2000 and checking on July 30, 2026 → exactly 26 years, 0 months, 0 days.
Age at a past event
Set date of birth and change "Age at date" to a wedding, graduation, or contract date to see exact age then.
Total days lived
The total-days card counts every calendar day from birth date through the as-of date (inclusive of the span between them).
Read the full guide
How to Use Age Calculator: Complete Guide (2026) - 5 min read
Frequently Asked Questions about Age Calculator
- How does the age calculator work?
- It subtracts the date of birth from the as-of date using calendar years, months, and days. If the day of the month has not been reached yet, it borrows from the previous month (using that month's real length). If the month has not been reached yet, it borrows a year. That is chronological age - not a fixed 30-day-month estimate.
- Can I calculate age on a past or future date?
- Yes. Leave "Age at date" as today for current age, or set it to any other date to answer questions like "How old was I on this date?" or "How old will I be on that date?" The date of birth cannot be after the as-of date.
- How do you handle leap years and February 29 birthdays?
- The calculator uses real calendar months, so February has 28 or 29 days depending on the year. For someone born on February 29, age on February 28 in a non-leap year is counted with normal day/month borrowing - not by inventing a Feb 29 that does not exist.
- What does total days mean?
- Total days is the number of whole calendar days between the birth date and the as-of date. It is useful for "days alive" style questions and is calculated from the calendar dates (timezone-safe), independent of the years/months/days breakdown.
- Is chronological age the same as medical or gestational age?
- No. This tool reports chronological age from date of birth. Medical contexts may use corrected or gestational age for infants; those need clinical formulas and are not covered here.
- Does my date of birth leave my device?
- No. The age calculator runs entirely in your browser. Dates are not uploaded or stored on a server.