Fuel Cost Per Mile CalculatorGas Per Mile & Cost Per Mile Calculator
Need to figure cost per mile for your vehicle? This free gas per mile calculator helps you calculate cost of gas per mile or per kilometer instantly. It works as a gallon per mile calculator, trip gas mileage calculator, and cost per mile fuel calculator — enter your fuel price and vehicle efficiency (MPG, L/100km, or km/L) to calculate petrol cost per mile with a complete step-by-step breakdown.
Getting started
How to calculate cost of gas per mile
1
Select unit system
Choose Imperial (MPG), Metric L/100km, or Metric km/L.
2
Enter fuel price
Enter the current fuel price per gallon or per liter.
3
Enter efficiency
Enter your vehicle fuel efficiency.
4
Read cost
Your cost per mile (or per km) appears instantly.
The calculation
Step-by-step: how your cost per mile was calculated
1
Divide fuel price by MPG
Cost per mile = Fuel Price per gallon / MPG
= $3.50 / 28
2
Scale to 100 miles for budget context
Cost per 100 miles = Cost per mile x 100
= $0.1250 x 100
A daily commute of 30 miles = $3.75 in fuel each way.
Formulas
Gas per mile formula — how to figure cost per mile
Imperial (MPG)
Cost per mile = Fuel price per gallon / MPG
Metric (km/L)
Cost per km = Fuel price per liter / km/L
Metric (L/100km)
Cost per km = (Fuel price per liter x L/100km) / 100
Reference Table
Cost per mile by vehicle type — gas mileage price calculator reference
Scale to your fuel price: multiply each rate by (your price / $3.50).
Background Information
What is fuel cost per mile?
Fuel cost per mile is a rate -- it expresses how much you pay in fuel to travel a single unit of distance, regardless of how far you drive in total. If your fuel cost per mile is $0.12, then every mile you drive costs 12 cents in fuel: 10 miles costs $1.20, 100 miles costs $12.00, and so on.
This metric is especially useful when comparing vehicles. Unlike total trip cost (which depends on trip length) or annual fuel spend (which depends on how much you drive), cost per mile is a pure measure of how efficiently a vehicle converts fuel money into distance traveled.
The IRS uses a related concept for business mileage reimbursement -- the standard mileage rate covers fuel plus depreciation, insurance, and maintenance. Fuel cost per mile is typically 15-25% of that total.
Interpreting
Interpreting your cost per mile result
Under $0.08 per mile -- very efficient
This typically means a hybrid or plug-in hybrid at moderate fuel prices, or any vehicle in a country where fuel is less expensive.
$0.08-$0.13 per mile -- average efficiency
This represents most modern compact and midsize vehicles at US fuel prices. A typical result at $3.50/gal is $0.10-$0.12/mile.
$0.14-$0.20 per mile -- below average
Typical of larger SUVs, older vehicles, or cars in areas with high fuel prices. Annual fuel cost at 15,000 miles: $2,100-$3,000.
Over $0.20 per mile -- high fuel cost
Common for heavy trucks, performance vehicles, or drivers in high-price regions. At 15,000 miles/year, this is over $3,000 annually in fuel alone.
Tips & Common Mistakes
Quick tips for reducing fuel cost per mile
Check your true average MPG.
Your vehicle trip computer shows real-world efficiency, which is often 5-15% lower than the EPA label. Use the actual figure for accurate calculations.
Compare before you buy.
A $2,000 price premium for a hybrid that cuts fuel cost from $0.13 to $0.07/mile pays back in full at 33,000 miles.
Use the 100-mile figure for budgeting.
The per-100-miles cost is easier to use for monthly budgets. If you drive 1,200 miles/month and your cost per 100 miles is $12, your monthly fuel expense is $144.
Common mistakes when calculating cost per mile
Using rated MPG instead of real-world MPG
EPA-labeled fuel economy is measured under controlled conditions. Using the rated figure will understate your actual fuel cost per mile.
Forgetting that L/100km is inverted
With MPG and km/L, higher = better. With L/100km, lower = better. A result of 10 L/100km is good; 10 MPG is poor.
Confusing cost per mile with total cost per mile
Fuel cost per mile is just the fuel component. Total cost per mile -- which includes depreciation, insurance, maintenance, registration, and financing -- is typically 4-6x higher than fuel cost alone.
FAQ
Frequently asked questions
Q
What is fuel cost per mile?
Fuel cost per mile is the amount you spend on fuel for every mile (or kilometer) you drive. It is calculated by dividing the fuel price per gallon by your vehicle fuel efficiency in MPG (or using the equivalent metric formulas). At $3.50/gal and 28 MPG, your fuel cost per mile is $3.50 / 28 = $0.125 per mile. This rate is independent of trip length -- it applies equally to a 1-mile errand and a 1,000-mile road trip.
Q
What is the formula for fuel cost per mile?
For Imperial: Cost per mile ($) = Fuel Price per gallon / MPG. For Metric (km/L): Cost per km = Fuel Price per liter / km/L. For Metric (L/100km): Cost per km = (Fuel Price per liter x L/100km) / 100. All three formulas express the same physical relationship -- how much you pay for the fuel needed to cover one unit of distance.
Q
What is a typical fuel cost per mile in the US?
At $3.50 per gallon, a vehicle getting 28 MPG (typical midsize sedan) costs about $0.125 per mile in fuel. A full-size truck at 18 MPG costs $0.194/mile -- 55% more than the sedan. A hybrid at 48 MPG costs $0.073/mile. The average across the US fleet hovers around $0.10-0.18 per mile depending on current fuel prices and vehicle mix.
Q
Can I use this to compare two vehicles?
Yes -- this is one of the best uses of the fuel cost per mile calculator. Run the calculation with the same fuel price for each vehicle. The one with lower cost per mile is cheaper to fuel. For example: Vehicle A at 22 MPG costs $0.159/mile; Vehicle B at 38 MPG costs $0.092/mile -- Vehicle B saves $0.067 per mile.
Q
Does cost per mile include all driving costs?
No -- fuel cost per mile covers only the fuel component. True total cost per mile also includes depreciation, insurance, loan interest, maintenance, tires, and registration. The IRS standard mileage reimbursement rate (approximately $0.67/mile for 2024) includes all these components combined.
Q
How does fuel cost per mile change with fuel price?
Cost per mile scales directly and proportionally with fuel price. If gas rises 20% -- from $3.00 to $3.60 -- your fuel cost per mile also rises exactly 20%. Fuel efficiency (MPG) does not change, so improving efficiency is the only way to reduce the fuel-price-sensitivity of your per-mile cost.
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