MPG Calculator
Find your car's MPG fuel efficiency online. Enter distance in miles and gallons of fuel used to calculate fuel economy, trip fuel cost, and cost per mile.
About This Calculator
The MPG Calculator (Miles Per Gallon) helps you determine your vehicle's fuel efficiency quickly and accurately. Whether you are a daily commuter in the US monitoring rising fuel costs, a fleet manager tracking vehicle performance, or a road trip planner budgeting for an upcoming journey, this tool gives you instant MPG ratings and trip cost estimates. Fuel efficiency knowledge helps you save money, reduce your carbon footprint, and make informed decisions about vehicle purchases and driving habits.
The formula is straightforward: MPG = Distance (miles) / Fuel Used (gallons). For example, if you drive 250 miles and use 10 gallons of fuel, your fuel economy is 25 MPG. When you provide the fuel price per gallon, the calculator also estimates your total fuel cost (fuel used gallons multiplied by price per gallon) and your cost per mile (total cost divided by distance). The interactive Fuel Consumption chart shows how much fuel is needed at various distances at your calculated MPG, while the Trip Cost chart projects expenses across different trip lengths.
Regional Notes
United States: MPG is the standard fuel economy measure, and fuel is priced per US gallon (3.785 liters). The average fuel economy for new US vehicles in 2025 is approximately 25-28 MPG. Regular gasoline prices typically range from $3.00 to $4.50 per gallon depending on region and market conditions.
United Kingdom: While the UK uses miles for distance, fuel is sold in liters and fuel economy is often expressed in miles per imperial gallon (MPG imp) where 1 imperial gallon = 4.546 liters. UK MPG values are approximately 20% higher than US MPG for the same vehicle. This calculator uses US gallons; UK users should apply a conversion factor of approximately 1.201 to compare figures.
India: India primarily uses kilometers per liter (kmpl) rather than MPG. To convert kmpl to MPG (US), multiply by 2.352. For example, a car rated at 20 kmpl achieves approximately 47 MPG. Fuel in India is priced per liter, with petrol typically ranging from ₹100 to ₹110 per liter in most cities as of 2025.
Frequently Asked Questions
What is MPG and how is it calculated?
MPG stands for miles per gallon and measures how many miles a vehicle can travel on one gallon of fuel. It is calculated by dividing the total distance traveled in miles by the amount of fuel consumed in gallons. For example, if you drive 300 miles and use 12 gallons of fuel, your MPG is 300 divided by 12, which equals 25 MPG.
How do I calculate my car's MPG?
To calculate your car's MPG, fill the tank completely and record the odometer reading. Drive normally until you need to refuel. Fill the tank again and note how many gallons you added. Subtract the previous odometer reading from the current one to get the distance traveled. Divide the distance in miles by the gallons of fuel used. This MPG calculator does all the math instantly for you.
What is a good MPG for a car?
A good MPG depends on the vehicle type. For compact cars, 30-40 MPG is excellent. Sedans typically achieve 25-35 MPG, while SUVs and trucks average 15-25 MPG. The US average across all vehicles is about 25 MPG. In the UK, fuel economy is often measured in miles per imperial gallon, where a good figure is 40-60 MPG. Hybrid and electric vehicles can achieve 50 MPGe or more.
How does fuel price affect my trip cost?
Fuel price directly impacts your total trip cost. The higher the price per gallon, the more you pay for the same journey. To estimate your trip cost, divide your trip distance by your car's MPG to get gallons needed, then multiply by the fuel price per gallon. Our calculator shows your total fuel cost and cost per mile when you enter the fuel price.
What factors affect my car's MPG?
Several factors affect your car's MPG including driving habits like aggressive acceleration and braking, vehicle maintenance such as tire pressure and air filter condition, weather conditions like cold temperatures and headwinds, vehicle load from cargo and passengers, use of air conditioning, and driving environment with city driving typically yielding lower MPG than highway driving.
Is there a difference between US and UK MPG?
Yes, US gallons and UK imperial gallons are different sizes. One UK gallon equals approximately 1.201 US gallons. This means a vehicle rated at 40 MPG UK would be about 33 MPG US. Our calculator uses US gallons, which is the standard in the United States. UK users should note that their imperial MPG figure will be higher than the US MPG value for the same fuel efficiency.
How can I improve my car's fuel efficiency?
To improve your car's fuel efficiency, maintain proper tire pressure, use the recommended grade of motor oil, replace air filters regularly, avoid excessive idling, accelerate gradually and maintain steady speeds, remove excess weight from the vehicle, use cruise control on highways, and combine errands into fewer trips. Regular engine tune-ups can also improve MPG by up to 10%.
What is the difference between MPG and L/100km?
MPG (miles per gallon) and L/100km (liters per 100 kilometers) are two different ways to measure fuel economy. MPG is higher for more efficient vehicles, while L/100km is lower for more efficient vehicles. To convert, divide 235.21 by your MPG value to get L/100km. For example, 25 MPG is approximately 9.4 L/100km. Most countries outside the US and UK use L/100km.