Age Calculator
Calculate exact age, total days lived, and next birthday from two dates.
Inputs
Results update as you edit.
Age
35 years, 11 months, 21 days
Results update as the calculator inputs change.
Total days
13,140
Total weeks
1,877.1
Next birthday
May 15, 2026
Days until birthday
9
How to Calculate Exact Age
How Age Calculations Work
Age can be expressed as years, months, days, or total elapsed days. Calendar age is different from simply dividing days by 365 because months and leap years vary.
What Affects an Age Calculation?
Common Age Calculator Uses
Exact Age
Find years, months, and days on a chosen date.
Days Lived
Count total elapsed days between dates.
Birthday Countdown
See how long remains until the next birthday.
Frequently Asked Questions
Why not divide days by 365?
Calendar years have different lengths because of leap years, and months have different day counts.
Can I calculate age on a future date?
Yes. Set the as-of date to the future date you want to check.
How are leap day birthdays handled?
Leap day birthdays can be treated differently for legal purposes depending on jurisdiction.
Does time of day matter?
For most everyday uses, no. For legal or medical timing, exact time and time zone may matter.
What is total days lived?
It is the count of elapsed calendar days between the birth date and as-of date.