How to Calculate Your Exact Age in Years, Months and Days

Ask someone their age and they will give you whole years. Forms, insurance policies, exam eligibility and school admissions often need more: years, months and days, measured to a specific date. Doing that by hand is easy once you follow a fixed order.

The method: years, then months, then days

1. Count the whole years from your birth date up to the last birthday before the target date.
2. Count the whole months from that birthday up to the target date.
3. Count the remaining days.

Example: born 15 June 1995, age on 27 October 2026.

• 15 June 1995 to 15 June 2026: 31 years
• 15 June 2026 to 15 October 2026: 4 months
• 15 October to 27 October: 12 days

Age: 31 years, 4 months, 12 days.

Why month lengths cause trouble

Months have 28, 29, 30 or 31 days, so “one month” is not a fixed number of days. If you were born on the 31st and the target month has only 30 days, many methods treat the last day of that month as your monthly anniversary. That is why two calculators can occasionally differ by a day: they made a different choice at a month end. Neither is “wrong” as long as the method is consistent.

Birthdays on 29 February

Someone born on 29 February 2000 has a real birthday only in leap years. On 27 October 2026 they are 26 years, 7 months and 28 days old. In non-leap years, most legal systems and calculators treat 28 February (some use 1 March) as the day the next year of age is completed. This site’s calculator uses 28 February, so the next birthday shows as 28 February 2027.

Age in total days, weeks or months

Sometimes you want one big number: how many days you have been alive, or your age in months for a baby’s growth chart. Count the days between the two dates, including every leap day in between.

For the 15 June 1995 example, that is 11,457 days, or 1,636 weeks and 5 days, or 376 months and 12 days. A useful sanity check: 31 years × 365 days = 11,315, plus 8 leap days and the 134 days since the last birthday.

The Date Difference Calculator gives total days, weeks and business days between any two dates.

Common uses

• School admission: age on the school’s cut-off date, not today.
• Exam and job eligibility: age on a date stated in the notice, often 1 January or 1 August.
• Insurance: some insurers use your age at your last birthday, others at your nearest birthday. Check which.
• Retirement planning: months matter when pension rules are based on exact dates.

For admissions with a fixed cut-off, try the Age at School Admission Calculator.

Frequently asked questions