Gas Mileage Calculator

Calculate your car's fuel economy

Fuel Economy

25.0 MPG

Cost per Mile

Annual Cost

$1,680

Rating

Average

Units

Distance (miles)

Fuel Used (gal)

Gas Price (per gallon)

Annual Distance (miles)

MPG

25.0

Efficiency Rating

Average

Cost per Mile

Cost per 100 Miles

$14

Annual Fuel Cost

$1,680

Cost Breakdown

Cost per Mile$0

Cost per 100 Miles$14

Annual Fuel Cost$1,680

What You'll Need

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Frequently Asked Questions

How do you calculate gas mileage?

Gas mileage (MPG) = Miles Driven ÷ Gallons Used. For example, if you drive 300 miles and use 12 gallons, your MPG = 300 ÷ 12 = 25 MPG.

Fill up completely, reset your trip odometer, then fill up again at the next stop
Divide trip miles by gallons pumped to get your real-world MPG
Track 3–5 fill-ups and average them for a more accurate reading
Your car’s dashboard MPG display is typically 5–10% optimistic compared to hand calculations

What is good gas mileage?

Good gas mileage depends on vehicle type: Economy cars: 30-40 MPG, Midsize cars: 25-35 MPG, SUVs: 20-30 MPG, Trucks: 15-25 MPG. Hybrids and electric vehicles achieve 40+ MPG equivalent.

The 2025 US average for new cars is 27.5 MPG (EPA combined)
Hybrids like Toyota Prius achieve 50–57 MPG; plug-in hybrids get 80–120 MPGe
Full-size trucks (F-150, Silverado) average 18–22 MPG combined
A 10 MPG improvement (25 to 35) saves ~$600/year at $3.50/gal and 12,000 miles

Vehicle Type	Typical MPG	Annual Fuel Cost (12K mi)
Economy Car	30–40 MPG	$1,050–$1,400
Midsize Sedan	25–35 MPG	$1,200–$1,680
SUV / Crossover	20–30 MPG	$1,400–$2,100
Full-Size Truck	15–22 MPG	$1,910–$2,800
Hybrid	40–57 MPG	$740–$1,050

How can I improve my gas mileage?

To improve MPG: 1) Maintain proper tire pressure, 2) Drive at steady speeds, 3) Avoid aggressive acceleration/braking, 4) Remove excess weight, 5) Use cruise control on highways, 6) Keep vehicle well-maintained, 7) Reduce idling time.

Underinflated tires reduce MPG by ~0.2% per 1 PSI drop – check monthly
Aggressive driving (hard acceleration, speeding) lowers MPG by 15–33% on highways
Every 100 lbs of extra weight decreases MPG by ~1%; clean out the trunk
AC use reduces MPG by 3–10%; at low speeds, roll windows down instead
A dirty air filter can reduce MPG by up to 10% – replace every 15,000–30,000 miles

What affects gas mileage?

Factors affecting MPG include: driving habits (aggressive vs smooth), vehicle maintenance, tire pressure, vehicle weight, aerodynamics, speed (optimal 50-60 mph), air conditioning use, and road conditions.

Optimal highway speed for fuel economy is 50–60 mph; MPG drops ~1% per mph above 60
City driving gets 15–25% worse MPG than highway due to stop-and-go idling
Cold weather (20°F vs 77°F) reduces MPG by 12–22% on short trips
Ethanol blends (E15, E85) reduce MPG by 4–27% compared to pure gasoline

Example Calculations

1300 Miles on 12 Gallons

Inputs

Distance300 miles

Fuel Used12 gallons

Gas Price$3.50/gallon

Annual Distance12,000 miles

Result

Fuel Economy25.0 MPG

Efficiency RatingAverage

Cost per Mile$0.14

Cost per 100 Miles$14

Annual Fuel Cost$1,680

MPG = 300 / 12 = 25.0 MPG (Average rating). Cost per mile = $3.50 / 25 = $0.14. Annual cost = (12,000 / 25) x $3.50 = 480 x $3.50 = $1,680.

2450 Miles on 10 Gallons (Efficient Sedan)

Inputs

Distance450 miles

Fuel Used10 gallons

Gas Price$3.50/gallon

Annual Distance15,000 miles

Result

Fuel Economy45.0 MPG

Efficiency RatingExcellent

Cost per Mile$0.08

Cost per 100 Miles$8

Annual Fuel Cost$1,167

MPG = 450 / 10 = 45.0 MPG (Excellent rating, 40+ MPG). Cost per mile = $3.50 / 45 = $0.078. Annual cost = (15,000 / 45) x $3.50 = 333.3 x $3.50 = $1,167.

Show all examples

Formulas Used

Miles per Gallon (MPG)

MPG = Distance (miles) / Fuel Used (gallons)

Calculates fuel economy by dividing miles driven by gallons consumed.

Where:

Distance= Miles driven between fill-ups

Fuel Used= Gallons of fuel consumed

Cost per Mile

Cost per Mile = Gas Price / MPG

Fuel cost for each mile driven.

Where:

Gas Price= Price per gallon of fuel

MPG= Calculated fuel economy

Annual Fuel Cost

Annual Cost = (Annual Miles / MPG) x Gas Price

Estimated yearly fuel expense based on driving distance and fuel economy.

Where:

Annual Miles= Estimated miles driven per year

MPG= Vehicle fuel economy

Gas Price= Price per gallon of fuel

Show all formulas

Understanding Gas Mileage

Gas mileage (MPG) measures how far you can drive on one gallon of fuel.

Better MPG saves money and reduces environmental impact.

Driving habits and vehicle maintenance significantly impact fuel economy.

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