Neil DeGrasse Tyson is known for dropping scientific knowledge on us via Twitter, and today was no different. Today, Tyson shared an interesting way to find your hat size using pi.

Being that today is Pi Day (March 14, or 3/14), Tyson's timing in sharing factoid on Twitter was perfect.

Lots of people struggle with finding a hat that fits well, and now knowing how that size is calculated, it's no wonder.

A few people were surprised at the information.

Others were confused as to how it is useful, since our heads aren't perfectly spherical (they don't have to be, that's just how hats are measured).

This isn't a universally useful piece of knowledge, apparently.

Several people appreciated the timing of Tyson's factoid.

There were puns aplenty.

Tyson is largely known for explaining complex scientific concepts in ways that are easy to understand. A person's hat size may not seem overly complicated, but practical uses for pi are always good to know.