Who Determined That A Circle Should Be Divided Into 360 Degrees?

Home » Why Are Circles 360 Degrees » Who Determined That A Circle Should Be Divided Into 360 Degrees?

Maybe your like

Get the Popular Science daily newsletter💡

Breakthroughs, discoveries, and DIY tips sent six days a week.

Email address Sign up Thank you!

Terms of Service and Privacy Policy.

_James M. Shook

Redfort Township, Miss. _

The same people who invented the wheel about 6,000 years ago: the Mesopotamians, who loved the number 60. It’s a useful and easily divisible number, which made it ideal for both early mathematics and commercial trade. The Mesopotamians passed their base-60 numerical system to the ancient Egyptians, who used it to divide a circle into 360 degrees, Mary Blocksma writes in her book Reading the Numbers.

The 360-degree circle worked out great: The Egyptians loved perfect triangles, and exactly six of them fit into a circle. Therefore, six triangular slices of 60 degrees each made for a sensible 360-degree dissection of a circle. The Egyptians, who invented the degree symbol, also came up with the first calendar based on a 360-day year, which is only off by 5.25 days. Since then, the 360-degree circle has more than stood the test of time, it has made its mark on time itself: When time was first recorded on the face of a circle, it was an easy leap to divide hours into 60 minutes and minutes into 60 seconds.

products on a page that says best of what's new 2025

2025 PopSci Best of What’s New

The 50 most important innovations of the year

See it

Tag » Why Are Circles 360 Degrees