Enter your date of birth to calculate your exact age
Your exact age is the difference between your date of birth and today's date, broken down into full years, remaining months, and leftover days. This is different from simply subtracting birth years — a person born on December 31, 2000 is still 24 years old on December 30, 2025, not 25.
The calculator above updates automatically when you enter your date of birth. It accounts for leap years, variable month lengths, and the exact calendar position of your birthday.
The calculation works in three steps. First, full years are counted — the number of times your birthday has passed since you were born. Second, the remaining months after the last birthday are counted. Third, the remaining days after the last full month are added.
For example, someone born on March 15, 1990 on October 20, 2026 would be 36 years, 7 months, and 5 days old — not simply 36.
Beyond years, months, and days, age is sometimes expressed in other units depending on context. A newborn's age is typically tracked in weeks. A medical record may log age in total months for children under two. Legal age thresholds — 18 for voting, 65 for retirement — are defined in full years only, regardless of months or days.
In most countries, you officially turn a new age on your birthday — the morning of, not the day before. Japan historically used a system where everyone aged one year on New Year's Day regardless of birthday, though this was officially abolished in 1950.
People born on February 29 — a date that only exists in leap years — officially celebrate their birthday on either February 28 or March 1 in non-leap years depending on the country and legal system. In the UK and Hong Kong, the legal birthday is March 1. In most other countries it is February 28. This calculator uses February 28 as the non-leap equivalent for age calculation purposes.
Enter your date of birth into the calculator above. It subtracts your birth date from today and returns your age in years, months, and days — accounting for leap years and varying month lengths automatically.
Full years alone do not capture your precise age. If you were born on November 1 and today is October 31, you are technically still one day away from your next birthday — the years-only figure would overcount by one year. The years, months, and days breakdown is always accurate.
Yes. February 29 birthdays and the extra day in leap years are handled correctly. A person born on February 29, 2000 turns 26 on February 28 or March 1, 2026 depending on convention — this calculator uses February 28.
This calculator uses today's date as the reference point. For a future reference date, you would need to manually note the difference between the two dates.
Zero years, zero months, zero days — meaning today is your birthday. The result will show 0y 0m 0d.
Legally, age is measured in full years only. You are considered to reach a new year of age on the anniversary of your birth date. Days and months are not counted for legal thresholds such as voting age, driving age, or retirement eligibility.