Your dashboard shows MPG. It doesn’t show the number that actually matters for your wallet: cents per mile. One division — price ÷ MPG — and every trip, commute, or car comparison becomes a dollar figure instead of an efficiency score.
The formula
cost per mile = price per gallon ÷ MPG. At $4.00/gallon:
- 15 MPG (truck / SUV) — $0.267/mile, or 27¢.
- 25 MPG (average sedan) — $0.160/mile, or 16¢.
- 35 MPG (efficient sedan) — $0.114/mile, or 11.4¢.
- 50 MPG (hybrid) — $0.080/mile, or 8¢.
- EV at 3.5 mi/kWh, $0.15/kWh — $0.043/mile, or 4.3¢.
Why fleet managers live by this
A delivery company running 200 trucks 30,000 miles each per year is moving 6 million miles. A 1¢/mile improvement is $60,000/year. That’s why fleet vehicle purchases, route optimization, and maintenance decisions are all benchmarked in cents per mile, not MPG. The same logic scales down to one driver — just with smaller totals.
Your personal number
Two cars at 22 vs 32 MPG, $4 gas, 12,000 miles/year: 18.2¢/mile × 12k = $2,180 vs 12.5¢/mile × 12k = $1,500. That’s $680/year, or $6,800 over a decade. Whether that matters depends on other costs — but at least you’re comparing dollars to dollars instead of trying to do MPG math in your head.
Enter miles driven, gallons used, and price per gallon. Get MPG, L/100km, and cost per mile in one pass.