There is at least one Friday the 13th every year, and at most three in a single year.

The short answer

  • In the long run, Friday the 13th happens about 1.7 times per year on average.
  • That’s roughly once every 212 days or so.

How often it can happen in a year

  • Minimum: 1 Friday the 13th (some years only have one).
  • Typical: 1 or 2 is most common across real calendar years.
  • Maximum: 3 Friday the 13ths in one year (for example, 2015 and again in 2026: February, March, November).

A neat calendar fact: any month that starts on a Sunday will have a Friday the 13th.

Over the long term

Mathematicians looked at a full 400‑year cycle of the Gregorian calendar (because the calendar pattern repeats every 400 years).

  • Over 400 years, there are 688 Fridays that fall on the 13th.
  • That works out to an average of 688 ÷ 400 ≈ 1.72 Friday the 13ths per year.
  • Another way to say it: Friday the 13th shows up about once every 212.35 days.

Fun, slightly spooky detail

Statistically, the 13th of a month is a bit more likely to be a Friday than any other weekday in the Gregorian calendar, thanks to how leap years and month lengths line up.

TL;DR: There is always at least one Friday the 13th each year, never more than three, and over time you get about 1.7 of them per year on average.