Age Calculator
Calculate exact age and days until next birthday
How to use Age Calculator
Calculate your exact age in years, months and days. See days until your next birthday. Free online age calculator tool.
When do you need to calculate exact age?
Age calculations seem simple but edge cases make manual arithmetic error-prone — leap year birthdays (February 29), end-of-month dates, and the question of whether you include the current day all affect the result.
- Identity verification: Check if a person meets an age requirement — 18 for voting, 16 for driving, 21 for certain US alcohol purchases. A day's difference can matter legally.
- Medical and insurance applications: Insurance premiums and medical dosages are often age-dependent. Insurers calculate age at last birthday or nearest birthday — knowing your exact age helps you understand which bracket applies.
- HR and payroll: Calculate statutory retirement dates, pension eligibility, or seniority-based benefits that depend on exact years of service.
- Astrology and numerology: Calculate exact age in days, weeks, months, and years for life path calculations.
- Curiosity: How many days old are you? How many days until your next milestone birthday (30, 40, 50)?
Leap year birthdays: People born on February 29 (about 1 in 1,461) only have a "real" birthday every 4 years. Legally, most jurisdictions treat March 1 as their birthday in non-leap years.
Frequently Asked Questions
How is age calculated — at last birthday or nearest birthday?
In everyday use, age is at last birthday — you are 34 until you turn 35. In actuarial science and some insurance calculations, 'age nearest birthday' rounds to the closest birthday. This calculator uses the standard last-birthday convention.
What is my age in days?
Multiply your age in years by 365.25 (accounting for leap years) for an approximation. For the exact count, the calculator subtracts your birth date from today's date, which accounts for all leap years precisely.
How do I calculate age in months?
Count the complete calendar months between the birth date and today. If born on March 15 and today is April 10, that is 0 complete months (March 15 to April 15 would be 1 month). If today is April 20, it is still 1 month (the 15th has passed in April).
At what age does someone legally become an adult?
It varies by country and context: 18 in most of Europe, the UK and Australia (for voting, contracts). 21 in the US for alcohol. 16 in some countries for certain activities. 18 is the most common threshold internationally for full legal adult status.
Why do Asian cultures sometimes count age differently?
Traditional East Asian age reckoning (Korean, Chinese) counts a newborn as age 1 at birth (reflecting the ~9 months in the womb) and adds a year on each New Year's Day rather than on the birthday. This can make someone 1-2 years 'older' than Western age. South Korea officially switched to the Western system in June 2023.
Age calculator vs birthday countdown vs date difference calculator
An age calculator specifically computes years, months, and days from a birth date to today. A birthday countdown shows days until the next birthday. A date difference calculator is more general — it measures the interval between any two dates. All three perform similar date arithmetic; the difference is the framing. This tool combines all three: exact age, days lived, and days until next birthday.