The Surprising Origin of the Percent Symbol

The % symbol started as an abbreviation for the Italian word per cento. Over centuries, scribes gradually morphed the handwritten phrase into the slanted slash and two circles we use today.

During the Middle Ages, merchants often wrote per 100 in their ledgers to track interest rates and taxes. Eventually, they shortened this to p cento, which was later abbreviated with a line and a circle. This shorthand evolved over time until the letters were dropped entirely, leaving only the abstract symbols that represent the concept. It is fascinating that such a common mathematical tool began as simple handwriting shorthand.