Age Calculator
Enter your date of birth to get your exact age in years, months, and days. Also shows total days you've been alive, the day of week you were born, and how many days until your next birthday.
Dates
36
Years
6
Months
22
Days
13,352
Total days lived
162
Days until next birthday
1,907
Weeks lived
Monday
Day you were born
How It Works
Age calculation seems simple but has edge cases — particularly leap year birthdays (February 29). When someone born on Feb 29 celebrates their birthday in a non-leap year, most legal and civil systems treat March 1 as their birthday. The calculation works by finding the number of complete years elapsed, then counting remaining full months, then remaining days. The total 'days alive' count uses the simple difference between two calendar dates, accounting for leap years automatically.
Formula
Age = (Today − DOB) broken into full years, remaining full months, and remaining days. Days until birthday = next occurrence of birth month/day − today.
Frequently Asked Questions
How is exact age calculated?
Exact age is calculated by finding how many complete years have passed since the date of birth, then counting remaining complete months, then remaining days. For example, born on March 15, 2000, and today is June 14, 2026: age = 26 years, 2 months, 30 days. The key is counting only completed units — partial years/months/days don't count.
What happens with Feb 29 birthdays?
February 29 only exists in leap years (divisible by 4, with century-year exceptions). People born on Feb 29 typically celebrate on Feb 28 or March 1 in non-leap years. Legal systems vary — some countries use Feb 28, others use March 1. In our calculator, we use the standard JS Date handling which places the next birthday at March 1 in non-leap years.
Why does the age sometimes differ from simple year subtraction?
Subtracting birth year from current year gives approximate age — but if your birthday hasn't occurred yet this calendar year, that calculation overstates your age by 1. Exact age requires checking whether this year's birthday (same month and day) has already passed. If today is before your birthday this year, subtract one extra year from the simple calculation.
How many days are in a year for age calculations?
For 'total days lived', we count actual calendar days between the date of birth and today — including leap years, which have 366 days. This is why two people who are both '26 years old' may have different total day counts depending on how many February 29ths fell in their lifespans. On average, a year has 365.2425 days.
What is the legal age of majority in India?
In India, the age of majority is 18 years under the Indian Majority Act, 1875. For voting (Constitution Article 326), electoral rolls, and marriage registration, 18 is the minimum age. For purchasing alcohol (varies by state: 21 in Maharashtra, 18 in Goa and some others). For a driving licence: 16 for non-geared vehicles, 18 for geared vehicles.
Can I calculate the age between two custom dates?
Yes — instead of using today's date as the end date, you can enter any target date to find the age or duration between two specific dates. This is useful for calculating the age of a business, the duration of an investment, years until retirement, or any other interval between two known dates.