Born on February 29: How Leap Day Birthdays Work

How people born on 29 February count their age and birthdays, when they legally turn 18 or 21, and how rare a leap day birthday really is.

People born on 29 February — sometimes called leaplings or leap-year babies — have a birthday that only appears on the calendar once every four years. It raises some genuinely interesting questions about age, birthdays and the law. Here’s how it all works.

How often does a "real" birthday come around?

February 29 exists only in leap years, which occur roughly every four years — with the century exception (1900 wasn’t a leap year, 2000 was). So a leapling gets a calendar-accurate birthday about once every four years. In the three years between, they celebrate on either 28 February or 1 March, depending on preference.

How rare is it? Roughly 1 in 1,461 people are born on a leap day — there’s one 29 February in every 1,461 days. That works out to a few million leaplings worldwide.

Does their age count normally?

Yes. Age is counted in completed years from the date of birth, exactly like everyone else. A leapling born on 29 February 2000 is the same age as someone born on 28 February or 1 March 2000 — the missing calendar birthday doesn’t slow down the count. They simply mark the occasion on an adjacent day in common years. An age calculator handles a 29 February birth date correctly and counts every real calendar day.

When do they legally turn 18 or 21?

This is where it gets jurisdiction-specific. In a non-leap year, there’s no 29 February, so the law has to decide which day counts as the birthday for legal purposes:

  • In some places, a leapling is considered to reach the new age at the start of 1 March.
  • In others, the milestone is treated as falling on 28 February.

The difference rarely matters in practice, but it can affect the exact day someone turns 18 or 21 in a non-leap year. If it matters for something official, check the rule for your specific country or state.

Fun facts about leap day

  • The odds of being born on 29 February are about 1 in 1,461.
  • Some leaplings jokingly count their “leap birthdays” — turning “8” after 32 years.
  • Leap day has traditions of its own, including the custom of proposals on 29 February.

Counting a leapling’s age and milestones

To see a leapling’s exact age on any date — including how many actual 29 Februarys they’ve lived through — enter 29 February as the birth date in the age calculator. For the next leap-day birthday specifically, the birthday countdown finds the next 29 February.

Born on a leap day? See your exact age, leap days included, with the age in days calculator.
FAQ

Frequently asked questions

How does someone born on 29 February age?
Exactly like everyone else — age counts completed years from the birth date. The missing calendar birthday in common years does not change the count.
When do leaplings celebrate in non-leap years?
Most celebrate on 28 February or 1 March. Which one is personal preference, though the law may treat one as the official date for milestones.
When does a leapling legally turn 18 or 21?
It depends on the jurisdiction: some treat the milestone as 1 March, others as 28 February, in years without a 29 February. Check your local rule if it matters.
How rare is a leap day birthday?
About 1 in 1,461, because there is one 29 February in every 1,461 days. That is a few million leaplings worldwide.