How monthly gas cost is estimated
Most people know their commute better than their monthly odometer reading. This calculator starts there, converts a typical week into an average month, then adds the rest of your driving.
Formula
Monthly miles = Daily miles × Days/week × 52 ÷ 12 + Other miles
Monthly gas cost = Monthly miles ÷ MPG × Price per gallon
Worked example
A 30-mile round trip 5 days a week is about 650 miles a month. Adding 300 miles of other driving gives 950 miles. At 28 MPG and $3.50/gal, that is about $119 a month, or $3.75 per commute day.
What the result means
The commuting share shows how much of your fuel bill is tied to getting to work — useful when weighing a remote day, a carpool or a more efficient car. The price-sensitivity figure tells you how exposed your budget is to swings at the pump.
Assumptions and limitations
- Real MPG varies with speed, weather, traffic and load; city and highway driving often differ.
- Gas prices change and vary by region — enter what you actually pay.
- Already know total monthly miles? The fuel cost calculator takes them directly. For the full per-mile cost of a car, see the cost per mile calculator.