What Is Mole Day? - Date and How to Celebrate

Celebrate Mole Day and learn about Avogadro's Number

The mole is the traditional mascot for Mole Day.

Michael David Hill/Creative Commons

What Is Mole Day?

Avogadro's number is the number of particles in a mole of a substance. Mole Day is an unofficial chemistry holiday celebrated on a date that relates to Avogadro's number, which is approximately 6.02 x 1023. The purpose of Mole Day is to foster an interest in chemistry.

When Is Mole Day?

In the US, this is usually October 23rd between 6:02 am and 6:02 pm. (6:02 10/23). Alternate observance dates for Mole Day are June 2 (6/02 in MM-DD format) and February 6 (6/02 in DD-MM format) from 10:23 am to 10:23 pm.

Mole Day Activities

Whenever you choose to celebrate it, Mole Day is a great day to think about chemistry in general and the mole in particular. Here are some Mole Day activities for you:

  • Determine how much aluminum foil you would need to make a 0.5 mole aluminum sculpture (of a mole, if you like). Weigh out the foil and get creative.
  • Write your own mole joke. Examples of mole jokes include: Where did Avogadro stay on his vacation? A mole-tel.
  • Make up a song about the mole. You should get bonus points if you make a video and upload it to YouTube.
  • Determine how much water is in one mole of water. Can you drink that amount?
  • Experimentally determine Avogadro's number.

How Did Mole Day Get Started?

Mole Day traces its origins to an article that appeared in The Science Teacher magazine in the early 1980s about a high school chemistry teacher's reasons for celebrating the day. The idea for Mole Day took root. The National Mole Day Foundation was formed on May 15, 1991. The American Chemical Society plans National Chemistry Week so that Mole Day falls within the week. Today Mole Day is celebrated around the world.


  • Wang, Linda (2007). "National Chemistry Week Celebrates 20 Years." Chemical & Engineering News. 85 (51).
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Your Citation
Helmenstine, Anne Marie, Ph.D. "What Is Mole Day? - Date and How to Celebrate." ThoughtCo, Aug. 25, 2020, thoughtco.com/what-is-mole-day-and-how-to-celebrate-607762. Helmenstine, Anne Marie, Ph.D. (2020, August 25). What Is Mole Day? - Date and How to Celebrate. Retrieved from https://www.thoughtco.com/what-is-mole-day-and-how-to-celebrate-607762 Helmenstine, Anne Marie, Ph.D. "What Is Mole Day? - Date and How to Celebrate." ThoughtCo. https://www.thoughtco.com/what-is-mole-day-and-how-to-celebrate-607762 (accessed June 10, 2023).