Age Calculator
Find your exact age in years, months and days, how many days you have lived, and how long until your next birthday. You can also calculate the age on any past or future date.
Enter your details above — results update as you type.
Formula and calculation
Worked example
Born on March 15, 1990, and calculated on October 16, 2026: the exact age is 36 years 7 months 1 day. That is 13,364 days lived, and the next birthday is Monday, March 15, 2027, 150 days away.
How age is counted
This calculator counts completed years: on the day before your birthday you are still the younger age, and the count changes on the birthday itself. Some traditions (notably in Korea) count age differently — everyone gains a year on January 1 — and a person can be “one” at birth. When a form asks for your age, the completed-years number is almost always what is wanted.
What the results mean
- Age
- Your age in whole years on the chosen date — the number people normally mean by “age”.
- Exact age
- The exact age as years, months and days, counting calendar months rather than an average month length.
- Days lived
- Total days lived between the birth date and the chosen date — useful for “days until” milestones and for forms that ask in days.
- Next birthday
- The date of your next birthday after the chosen date.
- Days until next birthday
- How many days until that next birthday. On a birthday itself, this shows the following year's date.
- Born on a
- The day of the week you were born — a surprisingly common pub-quiz question.
Frequently asked questions
How do I calculate my exact age in years, months and days?
Count whole years from your birth date to today, then whole months past that anniversary, then the remaining days. This calculator does that calendar arithmetic for you — the answer is not simply “days divided by 365.25”, which can be off by a day around anniversaries.
Why is my age in days different in different calculators?
Most disagreements come from whether the birth day itself is counted as day one. This calculator counts the number of full days between the two dates — someone born yesterday is one day old today. Leap days are always included; they are simply part of the calendar.
What if I was born on February 29?
Feb 29 birthdays are treated conventionally: in a non-leap year the anniversary is counted on March 1. So a leap-day baby is a year older on March 1 in ordinary years, and on Feb 29 in leap years.