Car Fuel Consumption Calculator UK
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Reviewed by Calculator Editorial Team
Understanding your car's fuel consumption is essential for managing costs and environmental impact. This calculator helps UK drivers estimate their vehicle's fuel efficiency in miles per gallon (mpg) and annual fuel costs.
How to Use This Calculator
To calculate your car's fuel consumption:
- Enter the distance traveled in miles
- Enter the amount of fuel purchased in liters
- Select your fuel type (petrol or diesel)
- Click "Calculate" to see your fuel efficiency and cost estimates
The calculator will display your car's fuel consumption in miles per gallon (mpg) and estimate the annual fuel cost based on current UK average prices.
Fuel Consumption Formula
The fuel consumption is calculated using the following formula:
Fuel Consumption (mpg) = (Distance traveled in miles) / (Fuel purchased in gallons)
Where fuel purchased in gallons is converted from liters using the conversion factor:
Fuel in gallons = Fuel in liters × 0.219969
The annual fuel cost is calculated by:
Annual Cost = (Annual distance in miles / Fuel consumption in mpg) × Fuel price per gallon
Worked Example
Let's calculate the fuel consumption for a car that travels 12,000 miles in a year and purchases 450 liters of petrol at an average UK price of £1.40 per liter.
- Convert liters to gallons: 450 × 0.219969 = 99.49 gallons
- Calculate mpg: 12,000 miles / 99.49 gallons ≈ 120.5 mpg
- Calculate annual cost: (12,000 / 120.5) × £1.40 ≈ £132.50
This means the car achieves approximately 120.5 miles per gallon and costs around £132.50 per year to fuel.
UK Fuel Consumption Standards
The UK government sets minimum fuel efficiency standards for new cars. These standards are based on the Worldwide Harmonized Light Vehicles Test Procedure (WLTP) and are expressed in miles per gallon (mpg).
| Vehicle Type | Minimum MPG (Urban) | Minimum MPG (Extra Urban) | Minimum MPG (Combined) |
|---|---|---|---|
| Petrol Cars | 54.3 | 63.7 | 58.7 |
| Diesel Cars | 63.4 | 72.8 | 67.6 |
| Alternative Fuel Vehicles | 130.0 | 130.0 | 130.0 |
Note: These standards apply to new cars registered on or after 1 September 2017. Older vehicles may have different efficiency ratings.
Frequently Asked Questions
- What is the difference between mpg and litres per 100 km?
- Miles per gallon (mpg) is a measure of fuel efficiency commonly used in the UK, while litres per 100 km is used in many other countries. You can convert between the two using the formula: 1 mpg ≈ 0.425 litres per 100 km.
- How accurate is this calculator?
- The calculator provides an estimate based on the inputs you provide. For precise fuel consumption figures, consult your vehicle's manufacturer or use a professional fuel consumption tester.
- Why does my car's actual fuel consumption differ from the calculator's estimate?
- Several factors can affect actual fuel consumption, including driving conditions, vehicle maintenance, and fuel quality. The calculator provides a baseline estimate based on your inputs.
- How can I improve my car's fuel efficiency?
- To improve fuel efficiency, maintain proper tire pressure, drive smoothly, avoid excessive idling, and use cruise control on motorways. Regular vehicle servicing can also help.
- Is this calculator suitable for electric vehicles?
- This calculator is designed for petrol and diesel vehicles. For electric vehicles, use a dedicated electric vehicle range calculator.