Fuel Mileage Calculator
Calculate your vehicle fuel mileage in MPG US, MPG UK, km/L, and L/100km. Enter distance traveled and fuel used for instant fuel economy results with trip cost estimates.
About This Calculator
The Fuel Mileage Calculator helps you measure your vehicle fuel efficiency in all major units used worldwide. Enter the distance you have traveled and the fuel you have used, and instantly see your fuel mileage in miles per US gallon (MPG), miles per UK gallon (MPG UK), kilometers per liter (km/L), and liters per 100 kilometers (L/100km). Whether you are tracking your daily commute, planning a road trip, or evaluating a potential vehicle purchase, this calculator provides a complete picture of fuel economy across every measurement system with optional trip cost estimation.
How Fuel Mileage Is Calculated
The calculator converts all inputs to a consistent base unit before computing each metric. If you enter distance in miles and fuel in gallons, MPG US is simply distance divided by fuel. For MPG UK, the same miles are divided by fuel gallons converted to imperial gallons (multiplied by 0.832674). For metric results, miles are converted to kilometers and gallons to liters using standard conversion factors: 1 mile = 1.60934 kilometers, 1 US gallon = 3.78541 liters.
L/100km is the inverse of km/L multiplied by 100 — a lower value means better fuel economy. This is the standard unit in Europe, Canada, Australia, and most of the world. MPG (both US and UK) uses a larger-number-is-better scale, which can cause confusion when comparing across systems. Entering a fuel price also estimates the total fuel cost for your trip.
Regional Notes
United States: Fuel mileage is universally expressed in miles per US gallon (MPG). The EPA provides official fuel economy ratings for all new vehicles, and a typical sedan achieves 30-40 MPG on the highway. US gallons are the smallest gallon unit at 3.785 liters.
United Kingdom: Fuel economy is expressed in miles per imperial gallon (MPG UK) on older vehicles and in many publications, though new car specifications increasingly use L/100km. The UK imperial gallon is 4.546 liters, about 20% larger than a US gallon, so the same car shows a higher MPG UK rating.
India and other metric countries: Fuel efficiency is typically given in km/L or L/100km. Indian car manufacturers quote both units, and government fuel efficiency standards use km/L. In Europe and Asia, L/100km is the dominant standard for vehicle specifications and regulation.
Frequently Asked Questions
How do I calculate fuel mileage?
Fuel mileage is calculated by dividing the distance traveled by the amount of fuel used. In US units, divide miles driven by gallons of fuel consumed to get MPG. In metric units, divide kilometers driven by liters of fuel used to get km/L. For L/100km, divide liters of fuel by kilometers driven and multiply by 100.
What is the difference between MPG US and MPG UK?
US and UK gallons are different sizes. A US gallon equals 3.785 liters while a UK imperial gallon equals 4.546 liters. This means the same vehicle will show a higher MPG value in UK gallons because a UK gallon is about 20% larger. To convert, multiply US MPG by 1.201 to get UK MPG.
What is a good fuel mileage for a car?
A good fuel mileage depends on your vehicle type. For US MPG, over 40 MPG is excellent, 30-40 MPG is good, and under 25 MPG is below average. In L/100km, under 6 L/100km is excellent, 6-8 L/100km is good, and over 10 L/100km is poor. Modern hybrid and electric vehicles can achieve over 50 MPG.
How can I improve my vehicle fuel economy?
Drive at steady speeds around 55-65 mph (90-105 km/h), maintain proper tire pressure, remove excess weight from your vehicle, avoid aggressive acceleration and hard braking, use cruise control on highways, reduce engine idling time, keep your vehicle properly maintained with regular oil changes and clean air filters, and use the recommended grade of motor oil.
How do I manually check my cars fuel mileage?
Fill your fuel tank completely, reset the trip odometer to zero, drive normally for at least 100 miles, then fill the tank again and note the gallons or liters pumped. Divide the distance driven by the fuel used. For example, 300 miles divided by 10 gallons equals 30 MPG. For L/100km, divide liters used by kilometers and multiply by 100.
Why do different countries use different fuel mileage units?
The US uses MPG with US gallons as part of its customary measurement system. The UK historically used MPG with imperial gallons but now also uses L/100km. Most other countries including Europe, Canada, Australia, and India use km/L or L/100km as standard metric units. This calculator supports all major units for worldwide use.
Is fuel mileage the same as fuel economy?
Fuel mileage and fuel economy are often used interchangeably to describe how efficiently a vehicle uses fuel. Fuel mileage is commonly expressed in miles per gallon (MPG) in the US and UK, while fuel economy can also be expressed in km/L, L/100km, or MPG. Both terms measure the relationship between distance traveled and fuel consumed.