A February 29 birthday comes round on the calendar once every 4 years, but a person born on that day still gets 1 year older every year. Here is how each kind of age works for a leap-day birthday.
Which day is the birthday in a common year?
In years without a February 29, people born on a leap day celebrate on either February 28 or March 1. AgeCountLab calculators use February 28. Legal rules on which date counts differ from country to country, so check with the relevant authority for official matters.
Age in years, months and days
Age still goes up once a year. Someone born on 29 February 2000 was 26 years old on 28 February 2026 by the February 28 convention. The months and days work the same way as any other birthday.
Age in days is unaffected
A day count has no birthdays at all. Day 1 is March 1 and every later day adds 1, so the Age in Days calculator works exactly as it does for any other date.
The half birthday is fixed
The half birthday is 6 calendar months after the birthday. August always has a 29th, so a leap-day baby’s half birthday is August 29 every year, even in the 3 years out of 4 when the real birthday is missing. The Half Birthday Calculator shows it with a countdown.
How rare is a leap-day birthday?
A 4-year cycle holds 1,461 days, and 1 of them is February 29. If births were spread evenly, about 1 person in 1,461 would be born on a leap day.
Zodiac sign and other facts
February 29 sits well inside Pisces (February 19 to March 20), so there is no cusp question. Use the Zodiac Sign Calculator or the What Day Was I Born tool for the rest of the birth-date facts.
