Fuel Consumption Calculator
Calculate fuel consumption and energy usage for combustion and electric vehicles
Online fuel consumption calculator
Our free fuel consumption calculator lets you quickly calculate fuel usage in liters per 100 km (L/100km) or miles per gallon (MPG) and optionally estimate trip costs. It supports both combustion vehicles (petrol, diesel, LPG) and electric vehicles (EVs). Simply enter the distance traveled and fuel or energy consumed — the fuel/electricity price is optional and only needed if you want cost estimates.
How to calculate fuel consumption?
Fuel consumption is expressed in liters per 100 km (L/100km) in the metric system, or miles per gallon (MPG) in the imperial system. The metric formula is: consumption = (fuel used in liters / distance in km) x 100. For example, if you used 35 liters of petrol over 500 km, your consumption is (35 / 500) x 100 = 7.0 L/100km. For electric vehicles, the same formula applies using kWh instead of liters.
MPG vs L/100km — imperial and metric conversion
Miles per gallon (MPG) is the standard fuel economy measure in the US and UK, while L/100km is used in most of the rest of the world. The conversion formula is: MPG = 235.215 / (L/100km). For example, 7 L/100km equals about 33.6 MPG, and 30 MPG equals about 7.84 L/100km. Our calculator supports both systems — simply toggle between Metric and Imperial modes to see results in your preferred units.
Typical fuel and energy consumption by vehicle type
City car (petrol)
5-7 L/100km (34-47 MPG) — small, economical cars like Fiat 500, Toyota Yaris
Sedan / estate (petrol)
7-10 L/100km (24-34 MPG) — mid-size family cars like Toyota Corolla, Skoda Octavia
SUV / crossover (diesel)
6-9 L/100km (26-39 MPG) — larger vehicles like Kia Sportage, VW Tiguan
Hybrid (HEV)
4-6 L/100km (39-59 MPG) — Toyota Prius, Hyundai Ioniq Hybrid
Plug-in hybrid (PHEV)
1-3 L/100km (78-235 MPG*) — electric and combustion modes combined
Electric vehicle (EV)
14-20 kWh/100km (3.1-4.4 mi/kWh) — Tesla Model 3, VW ID.3, Hyundai Ioniq 5
Electric vehicles — energy consumption
Energy consumption in electric vehicles is measured in kWh per 100 km (kWh/100km) or miles per kWh. A typical EV uses 14 to 22 kWh/100km (2.8-4.4 mi/kWh), depending on vehicle weight, driving style, and weather conditions. At an electricity price of around $0.20/kWh, driving 100 km in an EV costs $2.80-4.40, while a combustion car (7 L/100km at $1.60/L) costs about $11.20. That is a 60-75% saving on fuel costs.
How to reduce fuel consumption?
- Smooth driving — avoid harsh acceleration and braking, maintain a steady speed
- Proper tire pressure — under-inflated tires increase rolling resistance and fuel use by 5-10%
- Reduce highway speed — driving at 65 mph instead of 75 mph can cut consumption by 15-20%
- Turn off unnecessary systems — air conditioning can add 0.5-1 L/100km (1-2 MPG drop) to fuel use
- Regular maintenance — changing filters, oil and spark plugs keeps the engine at peak efficiency
- Reduce weight — remove unnecessary items from the trunk and detach roof racks when not in use
- Drive at optimal RPM — for petrol engines this is 2000-2500 RPM, for diesel 1500-2000 RPM
Frequently asked questions
How do I calculate my car's fuel consumption?
Fill the tank, reset the trip meter, drive your usual route, then fill up again. Consumption = (liters at second fill / km driven) x 100, or for MPG: miles driven / gallons used. Our calculator does the math for you.
What is MPG and how does it relate to L/100km?
MPG (miles per gallon) measures how many miles you can drive on one gallon of fuel. L/100km measures how many liters you need for 100 km. They are inversely related: MPG = 235.215 / L/100km. Higher MPG means better economy, while lower L/100km means better economy.
Is the fuel/electricity price required?
No, the price field is optional. If you only want to know your consumption (L/100km or MPG), just enter distance and fuel used. Cost calculations only appear when you provide a price.
Is an electric car cheaper to run?
Yes, energy cost per mile is 3-4 times lower than fuel. EVs also have lower maintenance costs (no oil, filters, clutch). The main expense is the purchase price and potential battery replacement.
How do I calculate trip cost?
Cost = (consumption L/100km / 100) x distance km x fuel price per liter. E.g. at 7 L/100km, 300 km trip, $1.60/L: (7/100) x 300 x 1.60 = $33.60. Leave the price field empty if you only need consumption figures.