Miles per Gallon Calculator

Q: How do I calculate miles per gallon (MPG)?

To calculate MPG, divide the total miles driven by the gallons of fuel used. For example, if you drove 350 miles on 12.5 gallons of gas, your MPG is 350 ÷ 12.5 = 28 MPG. Our calculator handles this automatically and also converts to km/L and L/100km.

Q: What is a good MPG for a car?

A good MPG depends on vehicle type. For conventional cars: 40+ MPG is excellent, 30-40 MPG is good, 25-30 MPG is average. SUVs and trucks typically get 20-30 MPG. Hybrid vehicles can achieve 50+ MPG, while EVs have equivalent MPGe ratings of 100+.

Q: How do I convert MPG to L/100km?

To convert MPG to L/100km (liters per 100 kilometers), divide 235.21 by the MPG value. For example, 30 MPG = 235.21 ÷ 30 = 7.84 L/100km. Lower L/100km values indicate better fuel efficiency. Our calculator performs this conversion automatically.

Q: How much CO2 does my car produce per mile?

A typical gasoline car produces about 8.89 kg of CO2 per gallon burned. If your car gets 25 MPG, it produces approximately 0.36 kg (0.79 lbs) of CO2 per mile. Diesel vehicles produce about 10.18 kg CO2 per gallon. Our calculator computes exact CO2 emissions based on your fuel consumption.

Q: How much can I save by driving a more fuel-efficient car?

Fuel savings depend on your driving habits and fuel prices. At $3.50/gallon driving 15,000 miles/year: A car getting 30 MPG costs $1,750/year in fuel. A 20 MPG vehicle costs $2,625/year - that's $875 more annually or $4,375 over 5 years. Use our comparison calculator for personalized savings estimates.

Q: What's the difference between US and UK gallons?

A US gallon equals 3.785 liters while a UK (Imperial) gallon equals 4.546 liters - about 20% larger. This means UK MPG figures are higher than US MPG for the same vehicle. Our calculator supports both units for accurate conversions regardless of your location.

Calculate MPG (miles per gallon), convert to L/100km, estimate fuel costs, compare vehicle efficiency, and track CO2 emissions with our comprehensive fuel economy calculator.

Miles per Gallon Calculator

Calculate MPG, estimate trip costs, and compare vehicle fuel economy

⛽ Calculate MPG

🚗 Trip Cost

⚖️ Compare Vehicles

💡 Quick Examples

City Driving Highway Trip European (km/L)

📏 Distance Traveled

⛽ Fuel Used

🔥 Fuel Type

⛽ Regular Gas

✨ Premium

🛢️ Diesel

🌽 E85 Flex

💡 Quick Examples

Weekend Trip Cross-State Drive Cross-Country

🗺️ Trip Distance

⛽ Your Vehicle's MPG

💵 Fuel Price (per gallon)

💡 Quick Examples

Sedan vs Truck Standard vs Hybrid

🚗 Vehicle 1

Vehicle Name

MPG Rating

🚙 Vehicle 2

Vehicle Name

MPG Rating

📅 Annual Miles Driven

💵 Fuel Price (per gallon)

Embed Miles per Gallon Calculator Widget

About Miles per Gallon Calculator

Welcome to the Miles per Gallon Calculator, a comprehensive fuel economy tool that helps you calculate MPG, estimate trip costs, compare vehicles, and track CO2 emissions. Whether you're monitoring your car's efficiency, planning a road trip budget, or comparing vehicles for a purchase decision, this calculator provides all the metrics you need.

How to Calculate Miles per Gallon (MPG)

Calculating your vehicle's fuel economy is simple with the MPG formula:

Miles Per Gallon Formula

MPG = Distance Traveled (miles) ÷ Fuel Used (gallons)

For example, if you drove 350 miles on 12.5 gallons of gas, your MPG would be: 350 ÷ 12.5 = 28 MPG.

Step-by-Step MPG Calculation

Fill your tank completely at a gas station and record your odometer reading (or reset your trip meter)
Drive normally until you need to refuel again (at least 100+ miles for accuracy)
Fill up again and note how many gallons it took to refill
Calculate the distance driven and divide by gallons used

Pro Tip: For the most accurate results, always fill your tank to the same level (full) and calculate MPG over multiple fill-ups to account for driving variations.

What is a Good MPG?

Fuel economy varies significantly by vehicle type. Here's how different MPG ratings compare:

MPG Range	Rating	Typical Vehicles
50+ MPG	Excellent (A+)	Hybrids, EVs (MPGe), small efficient cars
40-50 MPG	Very Good (A)	Compact cars, efficient sedans
30-40 MPG	Good (B)	Mid-size sedans, small SUVs
25-30 MPG	Average (C)	Crossovers, minivans
20-25 MPG	Below Average (D)	Full-size SUVs, large sedans
<20 MPG	Poor (F)	Full-size trucks, performance vehicles

Unit Conversions: MPG, L/100km, and km/L

Different countries use different fuel economy measurements. Our calculator automatically converts between all major units:

Unit	Used In	Conversion
MPG (US)	United States	Base unit
MPG (UK)	United Kingdom	US MPG × 1.201 = UK MPG
L/100km	Europe, Australia, Canada	235.21 ÷ MPG = L/100km
km/L	Japan, India, parts of Asia	MPG × 0.425 = km/L

Note: Lower L/100km values mean better fuel economy (less fuel per distance), while higher MPG or km/L values indicate better efficiency.

CO2 Emissions and Fuel Consumption

Every gallon of gasoline burned produces approximately 8.89 kg (19.6 lbs) of CO2. Diesel produces about 10.18 kg (22.4 lbs) per gallon. The calculator estimates your carbon footprint based on fuel consumption and type.

CO2 Emissions by Fuel Type

Fuel Type	CO2 per Gallon	CO2 per Liter
Regular Gasoline	8.89 kg	2.35 kg
Premium Gasoline	8.89 kg	2.35 kg
Diesel	10.18 kg	2.69 kg
E85 (Flex Fuel)	5.76 kg	1.52 kg

How to Improve Your MPG

You can significantly improve your fuel economy with these driving habits and maintenance tips:

Driving Habits

Drive smoothly - Avoid rapid acceleration and hard braking
Maintain steady speed - Use cruise control on highways
Reduce idling - Turn off engine if stopped for more than 60 seconds
Slow down - Aerodynamic drag increases exponentially with speed
Plan trips - Combine errands to reduce cold starts

Vehicle Maintenance

Keep tires inflated - Under-inflated tires reduce MPG by up to 3%
Regular tune-ups - A well-maintained engine runs more efficiently
Use recommended oil - The right viscosity reduces friction
Replace air filters - Clogged filters restrict airflow
Reduce weight - Remove unnecessary cargo from your vehicle

US vs. UK Gallon: Understanding the Difference

There's an important distinction between US and UK (Imperial) gallons:

US Gallon = 3.785 liters (128 fluid ounces)
UK Gallon = 4.546 liters (160 fluid ounces)

This means UK MPG figures are approximately 20% higher than US MPG for the same vehicle. Our calculator supports both units for accurate international comparisons.

Frequently Asked Questions

How do I calculate miles per gallon (MPG)?

To calculate MPG, divide the total miles driven by the gallons of fuel used. For example, if you drove 350 miles on 12.5 gallons of gas, your MPG is 350 ÷ 12.5 = 28 MPG. Our calculator handles this automatically and also converts to km/L and L/100km.

What is a good MPG for a car?

A good MPG depends on vehicle type. For conventional cars: 40+ MPG is excellent, 30-40 MPG is good, 25-30 MPG is average. SUVs and trucks typically get 20-30 MPG. Hybrid vehicles can achieve 50+ MPG, while EVs have equivalent MPGe ratings of 100+.

How do I convert MPG to L/100km?

To convert MPG to L/100km (liters per 100 kilometers), divide 235.21 by the MPG value. For example, 30 MPG = 235.21 ÷ 30 = 7.84 L/100km. Lower L/100km values indicate better fuel efficiency.

How much CO2 does my car produce per mile?

A typical gasoline car produces about 8.89 kg of CO2 per gallon burned. If your car gets 25 MPG, it produces approximately 0.36 kg (0.79 lbs) of CO2 per mile. Diesel vehicles produce about 10.18 kg CO2 per gallon.

How much can I save by driving a more fuel-efficient car?

Fuel savings depend on your driving habits and fuel prices. At $3.50/gallon driving 15,000 miles/year: A car getting 30 MPG costs $1,750/year in fuel. A 20 MPG vehicle costs $2,625/year - that's $875 more annually. Use our comparison calculator for personalized estimates.

What's the difference between US and UK gallons?

A US gallon equals 3.785 liters while a UK (Imperial) gallon equals 4.546 liters - about 20% larger. This means UK MPG figures are higher than US MPG for the same vehicle. Our calculator supports both units.

Additional Resources

Reference this content, page, or tool as:

"Miles per Gallon Calculator" at https://MiniWebtool.com/miles-per-gallon-calculator/ from MiniWebtool, https://MiniWebtool.com/

by miniwebtool team. Updated: Feb 01, 2026

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