Age Calculator

How age is calculated

The calculator subtracts your birth year from the current year, then removes one year if your birthday hasn't happened yet this year. This is the way age is counted in everyday life and in most legal systems: you turn 30 on your 30th birthday, not on 1 January.

Example: someone born on 20 November 1995 is 30 years old on 13 October 2026 (their 31st birthday is still a few weeks away), and 31 from 20 November 2026.

Born on 29 February

People born on 29 February have a real birthday only every four years. In non-leap years, the calculator considers the birthday reached on 1 March. Legal rules on the exact date differ between countries — some use 28 February, others 1 March — which can matter for things like reaching the age of majority.

Age in other units

• Months: years × 12 plus the months since your last birthday.
• Days: use the days-between-dates calculator with your birth date and today's date. Someone who has lived 10,000 days is about 27 years and 5 months old.
• Weeks: divide the number of days by 7.

Different ways of counting age

• International age (used here): starts at 0 at birth and goes up on each birthday.
• East Asian age reckoning: traditionally, a baby was 1 at birth and everyone gained a year at the new year. South Korea officially switched to international age for legal and administrative purposes in 2023.
• School year age: many education systems group children by calendar year of birth rather than exact age.

Practical uses

Exact age matters for eligibility thresholds — school entry, driving licence, retirement, insurance premiums, sports categories or age-restricted purchases. Always check how the relevant organisation defines the date (on the day, at the start of the year or at the start of the season).

Formulas and content last reviewed: October 2026 · About