Cost Per Mile (Fuel): The Simple Formula + Examples
- Formula: Fuel cost per mile = price per gallon ÷ MPG.
- Scaling: Trip fuel cost = cost per mile × trip miles.
- Why it works: It converts fuel economy into dollars without relying on “MPG intuition.”
What Cost Per Mile Means
Cost per mile is a simple conversion: it takes the two inputs most drivers know (fuel price and MPG) and turns them into a per-mile budget number. That makes it useful for everything from a daily commute to comparing two vehicles.
If you prefer cost per 100 miles (a slightly larger, often easier-to-compare number), start here: Fuel cost per 100 miles.
What We Know (Sourced)
The EPA fuel economy label is designed to help consumers compare fuel economy and cost-related information across vehicles. EPA’s label guidance explains the standardized sticker and the information it includes. Source: U.S. EPA — Learn about the fuel economy label.
DOE’s fuel economy guidance emphasizes that small efficiency improvements can add up in real fuel use over time, and it highlights practical strategies for reducing fuel consumption. Source: U.S. Department of Energy — Fuel Economy.
If you are comparing vehicles using standardized data, FuelEconomy.gov provides EPA fuel economy information and tools for consumer comparisons. Source: FuelEconomy.gov.
The Formula + Examples
You can also flip the same math into a “trip budget”:
| MPG (example) | Gas price (example) | Fuel cost per mile |
|---|---|---|
| 20 MPG | $3.50/gal | $0.175 |
| 30 MPG | $3.50/gal | $0.117 |
| 40 MPG | $3.50/gal | $0.088 |
Common Use Cases
1) Commute budgeting
Once you know cost per mile, commute fuel cost becomes simple multiplication. For a worked approach, see: Commute gas cost (weekly and monthly).
2) Road trip planning
Cost per mile is just the road trip formula written as a per-mile rate. If you want a full walkthrough, see: How to calculate fuel cost for a road trip.
3) Comparing two vehicles
Comparing cost per mile for two MPG ratings is often clearer than comparing MPG directly. If you are using standardized sticker data, combine this with EPA label basics: Understanding the EPA label.
Want a one-step answer?
Enter your gas price and MPG to calculate fuel cost per mile instantly.
Use the Cost Per Mile CalculatorWhat’s Next (Practical Steps)
- Use your local price: your budget changes more with fuel price than many people expect.
- Use your real MPG: track MPG over multiple fill-ups for a stable number.
- Compare scenarios: cost per mile is ideal for “before vs after” (roof box on/off, speed change, route change).
If your goal is to lower the number, start with high-impact habits: speed, aggressive driving, and idling.
Why It Matters
Cost per mile is not “extra math” — it is just a different view of the same fuel economy information that EPA and DOE publish for consumers. It helps you connect the sticker and your real fuel price to the thing you actually pay: dollars per mile driven. Sources: EPA label overview and DOE fuel economy guidance.
Frequently Asked Questions
Does cost per mile include maintenance and depreciation?
This article focuses on fuel-only cost per mile (gas price and MPG). Total ownership cost can include insurance, tires, maintenance, and depreciation — those vary widely by driver and vehicle.
Is cost per mile better than cost per 100 miles?
They are the same information at different scales. Cost per mile is ideal for trip planning. Cost per 100 miles can be easier for comparing vehicles. See: cost per 100 miles.
Where can I find official MPG data to plug into the formula?
For standardized comparisons of new vehicles, use the EPA label and FuelEconomy.gov. Sources: EPA and FuelEconomy.gov.