Gas Mileage Calculator · Practical guide
Cost of Gas per Mile Calculator
Enter distance, fuel used, and price to see what every mile of driving actually costs you.
At a glance
The Cost-per-Mile Formula
Your gas cost per mile is the fuel price divided by your MPG. At $3.50 per gallon and 30 MPG, each mile costs about 11.7 cents, or roughly $11.67 per 100 miles. Enter your distance, fuel used, and price above and the calculator computes this automatically.
Interactive tool
Gas Mileage Calculator
Enter your own values, then compare the result with the examples below.
Mileage Results
Worked Example
You drove 300 miles, used 10 gallons, and paid $3.50 per gallon. Total fuel cost is 10 × $3.50 = $35, so the cost per mile is $35 ÷ 300 = $0.117 per mile. A 40-mile daily commute at that rate costs about $4.67 a day, or roughly $93 a month in gas alone.
Cost per Mile at Common MPG Levels
Assuming gas at $3.50 per gallon:
| MPG | Cost per Mile | Cost per 100 Miles |
|---|---|---|
| 15 | $0.233 | $23.33 |
| 20 | $0.175 | $17.50 |
| 30 | $0.117 | $11.67 |
| 40 | $0.088 | $8.75 |
| 50 | $0.070 | $7.00 |
Why This Number Matters
Cost per mile makes fuel spending concrete. It lets you compare vehicles before buying, decide whether a road trip beats flying, and budget accurately for a new commute. Note that this covers fuel only — the IRS rate for total driving cost including wear and depreciation is much higher, around 70 cents per mile.
Frequently Asked Questions
How do I find cost per mile without tracking gallons?
Divide the price per gallon by your vehicle's MPG. For example, $3.50 divided by 25 MPG equals $0.14 per mile.
Does cost per mile include maintenance and insurance?
No. This calculator covers fuel cost only. Full ownership cost, including depreciation, maintenance, and insurance, is typically several times higher.
How much does a 1,000-mile road trip cost in gas?
At 30 MPG and $3.50 per gallon, a 1,000-mile trip uses about 33.3 gallons and costs roughly $117.
Can I use this with kilometers and liters?
Yes. Switch to the metric unit system and the calculator shows cost per kilometer and per 100 kilometers instead.