Journey Cost Calculator UK 2026 - Calculate Fuel Cost Per Mile

How Much Will Your Journey Cost?

Calculate exact fuel costs for any UK journey. Understand MPG, compare petrol vs diesel, and discover how electric compares.

Calculate Now Learn About MPG

Journey Fuel Cost Calculator

Enter your journey details to calculate the exact fuel cost.

Distance (miles)

Vehicle Type

Fuel Type

Price (pence per litre/kWh)

Your Journey Cost

Total Fuel Cost

£0.00

Cost Per Mile

Fuel Needed

0 L

Formula used:


                                (Distance ÷ MPG) × 4.546 × Price = Cost

Understanding MPG (Miles Per Gallon)

MPG (Miles Per Gallon) measures how far your car can travel on one gallon of fuel. The higher the number, the more fuel-efficient your vehicle is.

UK vs US Gallons

UK uses Imperial gallons (4.546 litres). US gallons are smaller (3.785 litres). A car rated 40 MPG (UK) would be rated 33 MPG in the US.

Real-World vs Official MPG

Manufacturer figures are tested in labs. Real-world MPG is typically 15-20% lower. Our calculator uses realistic figures based on actual driving data.

Typical MPG by Vehicle Type

Small Petrol Car 55 MPG

Medium Petrol Car 45 MPG

Medium Diesel Car 55 MPG

SUV (Petrol) 30 MPG

Hybrid 60 MPG

MPG to Litres per 100km Converter

European cars use L/100km (litres per 100 kilometres) instead of MPG. Lower numbers mean better efficiency — the opposite of MPG.

Conversion Formula:

L/100km = 282.48 ÷ MPG

MPG

L/100km

Quick Reference

MPG (UK)	L/100km	Efficiency
30	9.42	Poor
40	7.06	Average
50	5.65	Good
60	4.71	Excellent
70	4.04	Outstanding

Petrol vs Diesel: Which is Cheaper?

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Petrol

Cheaper per litre (~134p)
Lower purchase price
Better for short journeys
No DPF issues
Lower MPG than diesel

Best for: Under 12,000 miles/year, city driving

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Diesel

15-20% better MPG
Better for motorways
More torque for towing
Costlier per litre (~143p)
Higher maintenance costs

Best for: Over 12,000 miles/year, motorway driving

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Electric

Cheapest per mile (home)
No road tax (until 2025)
Low maintenance
Higher purchase price
Public charging expensive

Best for: Home charging, commuters

Cost to Drive 100 Miles (January 2026)

£15.25

Petrol (40 MPG)

£14.45

Diesel (45 MPG)

£7.00

EV Home (4 mi/kWh)

£17.50

EV Rapid (4 mi/kWh)

Route Fuel Optimisation Tips

1. Drive Smoothly

Gentle acceleration and anticipating traffic can improve MPG by 20-30%. Harsh braking wastes the energy you've already paid for.

2. Optimal Speed

55-65 mph is the sweet spot. Driving at 70 mph uses 9% more fuel than 60 mph. At 80 mph, you're using 25% more.

3. Check Tyre Pressure

Under-inflated tyres increase rolling resistance. Tyres 20% below recommended pressure waste 3-5% extra fuel.

4. Avoid Motorway Services

Motorway fuel costs 15-25p more per litre. Fill up before joining the motorway — a 50L tank costs £8-12 extra at services.

5. Use Supermarket Fuel

Tesco, Asda, Sainsbury's and Morrisons are typically 3-8p cheaper per litre than branded stations.

6. Compare Before You Fill

Compare fuel prices using PetrolPrices.co.uk to find the cheapest fuel near you. Differences of 10p+ per litre are common. Plus, use fuel loyalty cards to save even more.

PetrolPrices Tools

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Journey Planner

Find cheapest fuel stops along your route

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Frequently Asked Questions

Use the formula: Fuel Cost = (Distance in miles ÷ MPG) × 4.546 × Price per litre. For example, a 100-mile journey in a car doing 40 MPG with petrol at 134p/litre costs: (100 ÷ 40) × 4.546 × 1.34 = £15.23.

MPG stands for Miles Per Gallon - it measures how many miles your car can travel on one gallon (4.546 litres) of fuel. Higher MPG means better fuel efficiency. A typical UK car achieves 40-50 MPG, while efficient hybrids can exceed 60 MPG.

Divide 282.48 by your MPG figure. For example: 40 MPG = 282.48 ÷ 40 = 7.06 L/100km. Lower L/100km means better efficiency. European cars often quote L/100km while UK cars use MPG.

It depends on your mileage. Diesel costs more per litre (around 9p more) but diesel cars are typically 15-20% more fuel efficient. Diesel becomes cheaper if you drive over 12,000 miles per year. For lower mileage, petrol is usually more economical.

Based on January 2026 prices: Petrol car (40 MPG) costs approximately £15.25. Diesel car (45 MPG) costs approximately £14.45. Electric car costs £7-10 with home charging or £17-25 with public rapid charging.

In January 2026, the average petrol cost per mile is 13-16 pence, depending on your car's efficiency. A car achieving 40 MPG at 134p/litre costs approximately 15.2p per mile. More efficient cars (50+ MPG) can achieve under 13p per mile.

Yes, significantly. Home charging costs around 7-10p per mile versus 13-16p for petrol. However, public rapid charging (70p/kWh) can cost 17-25p per mile - sometimes more than petrol. The savings depend heavily on where you charge.

Drive smoothly (saves 20-30% fuel), maintain correct tyre pressure (saves 3%), remove roof boxes when not needed, use cruise control on motorways, avoid idling, and compare fuel prices using PetrolPrices.co.uk to find the cheapest stations near you.

Based on real UK fuel pricing data from PetrolPrices.co.uk. Journey cost calculations use current average fuel prices and typical vehicle efficiency figures. Actual costs may vary based on driving conditions, vehicle condition, and local fuel prices.

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