The 9/10-Cent Gas Price: How a Fraction of a Penny Adds Up to $1.2 Billion a Year
Have you ever looked closely at a gas station sign and wondered about the tiny 9/10 at the end of the price? That fraction is worth about $1.2 billion a year to American gas stations — and about $5 a year to you. Every gallon of gasoline sold in the United States ends in nine-tenths of a cent. There is no coin for it, no law that requires it, and you never actually pay it — the pump rounds your total to the nearest cent. Yet it has survived for more than ninety years, outliving the tax that created it and, as of 2025, the penny itself. All figures below are as of November 14, 2026, unless noted. AAA put the national average for regular gasoline at $3.84 a gallon that day. What the 9/10 Actually Is The 9/10 is nine-tenths of one cent — $0.009 — added to the price of each gallon. It is measured in mills. A mill is one-thousandth of a dollar, an old unit of account that survives in tax and accounting math. The United States never minted a mill coin, and it never needed to: the fracti...
