How to Calculate Your Exact Age (Years, Months, Days & Leap Years)
The simple method to calculate age in years, months and days — including how leap years and month-length differences affect the result.
Calculating exact age sounds trivial until you hit February, leap years, or different time zones. Here's the method that handles all three.
The Standard Method
Start from your birthdate and count up: full years first, then full months, then the leftover days.
- Subtract birth year from current year — that's your years.
- If the current month/day is before your birth month/day, subtract 1 year.
- Count the months from your last birthday to today — that's your months.
- The remaining days from the most recent month-anniversary are your days.
Example: born 14 March 1990, today is 28 June 2026. Last birthday: 14 March 2026. From there: 3 full months (March 14 → June 14), then 14 days. Age: 36 years, 3 months, 14 days.
Leap Year Edge Cases
If you were born on February 29, three out of four years don't contain your birthday. Most calculators (and most legal systems) treat your birthday as March 1 in common years. A few jurisdictions use February 28 — check local rules if it matters for legal age thresholds.
Time Zones
Age depends on a "today" value, which depends on time zone. A birthday entered as a local date but compared against UTC's today can shift by a day. The Age Calculator uses your browser's local time to avoid that drift.
Age in Other Units
- Total days alive: useful for milestone planning (e.g. your 10,000th day).
- Total weeks: divide days by 7.
- Total months: full months elapsed, not days ÷ 30.
Try it now
Open the Age Calculator →