Age Calculator
Enter your date of birth to find your exact age in years, months, and days.
Enter your date of birth to instantly calculate your exact age in years, months, and days. The calculator also shows your total days and weeks lived, and how many days are left until your next birthday.
Age carries legal and social significance across many areas of life. Different jurisdictions set minimum ages for driving (16–18), voting (18 in most countries), drinking (18–21), and retirement (60–67 depending on the pension system). Knowing your exact age in days or months also matters for insurance eligibility, academic enrollment deadlines, and travel documents that expire on specific birthdays.
Frequently Asked Questions
How is exact age calculated?
The calculator counts the full years, months, and remaining days between your birth date and today. For example, if you were born on March 15, 1990, and today is May 20, 2025, your age is 35 years, 2 months, and 5 days.
How many days have I lived?
Multiply your age in years by 365.25 (to account for leap years) as a quick estimate. The calculator computes the exact number by counting every day from your birth date to today.
What is a leap year and how does it affect age?
A leap year has 366 days instead of 365, occurring every 4 years (with exceptions for century years). If you were born on February 29, your "official" birthday is celebrated on March 1 in non-leap years in most countries.
How do I calculate my age in months?
Multiply completed years by 12 and add the remaining months. For example, 25 years and 3 months = 25 × 12 + 3 = 303 months. The calculator shows this total automatically.
How many weeks are in a year?
There are exactly 52 weeks and 1 day in a regular year (365 days ÷ 7 = 52.14...), and 52 weeks and 2 days in a leap year. Over a lifetime of 70 years, that's approximately 3,652 weeks.
What was the oldest verified human age?
The oldest verified human age belongs to Jeanne Calment of France — 122 years and 164 days (born 1875, died 1997). People who reach 100 are called "centenarians"; those who reach 110+ are called "supercentenarians".
How is age calculated for legal purposes?
For legal purposes, age is determined by the calendar date on the birth certificate, regardless of time zone or exact time of birth. You turn a specific age at the very beginning of your birthday — i.e., at 00:00:00 on that calendar date in the relevant jurisdiction.
How many days until I turn a milestone age (e.g., 30 or 50)?
To find the days until your next birthday, use the "days to next birthday" value shown by this calculator. For further milestones, calculate the exact target date and use a Date Difference Calculator to count from today to that date.
What is a half birthday?
A half birthday falls exactly 6 months after your birth date. For someone born on August 31, the half birthday is February 28 (or 29 in a leap year). Half birthdays are sometimes celebrated for children whose actual birthday falls during school holidays.
Does daylight saving time affect age calculations?
No — age is calculated purely based on calendar dates, not clock time. A person born on a daylight saving transition day has the same birthday as anyone else born on that calendar date. Time-of-birth only becomes relevant for rare legal purposes such as twin birth-order disputes.