MPG to Litres per 100km Converter

Convert miles per gallon to litres per 100 kilometres and vice versa. This converter works with both UK imperial gallons and US gallons, giving you precise fuel consumption figures for any vehicle.

MPG to L/100km Conversion Table

Here are common fuel economy values converted between UK MPG, US MPG, and litres per 100 kilometres. These figures help you compare fuel efficiency across different measurement systems.

Conversion Formulas

The maths behind fuel economy conversion is straightforward once you understand the relationship between different units. Here are the key formulas you’ll need.

Step-by-Step Conversion

Understanding the Difference

The UK and US measure fuel economy differently, which often causes confusion when comparing vehicles or reading specifications from different markets.

Why the Numbers Matter

When you see a car advertised with 30 MPG in the United States, the same vehicle would show 36 UK MPG. The car hasn’t become more efficient—it’s just measured with a larger gallon. This 20% difference catches many people out when importing vehicles or comparing international specifications.

Most European countries abandoned MPG decades ago in favour of litres per 100 kilometres. This metric makes more sense for planning journeys. If your car does 7 L/100km and you’re driving 400 km, you simply multiply: 7 × 4 = 28 litres needed. Try doing that with MPG and you’ll see why Europe switched.

British Motoring Context

The average family car in Britain manages around 38 MPG in real-world driving conditions. Petrol engines typically achieve 36 MPG, whilst diesel variants push closer to 43 MPG. If you’re getting 50 MPG or better, you’re doing well—either through efficient driving or a particularly frugal vehicle.

Modern hybrids regularly exceed 60 MPG, making them attractive for high-mileage drivers. Small city cars with efficient petrol engines can hit 55-60 MPG, whilst larger SUVs often struggle to break 35 MPG. These figures represent real driving, not the optimistic official test results.

Everyday Scenarios

Different vehicles suit different needs. Here’s what typical fuel consumption looks like across various vehicle types in British roads.

City Runabout

A small hatchback like a Vauxhall Corsa or Ford Fiesta with a modern petrol engine achieves 50-55 MPG (5.1-5.6 L/100km) in mixed driving. Perfect for nipping around town and the occasional motorway jaunt.

Family Saloon

Mid-size family cars such as the Volkswagen Golf or Vauxhall Astra typically return 40-45 MPG (6.3-7.1 L/100km). They balance practicality with decent fuel economy for the school run and weekend trips.

Executive Motor

Larger vehicles like the BMW 5 Series or Mercedes E-Class manage 35-40 MPG (7.1-8.1 L/100km) with efficient diesel engines. Their size and weight work against them, but modern engineering helps.

Performance Vehicle

Hot hatches and sports cars often sit around 25-30 MPG (9.4-11.3 L/100km). You’re paying for performance, not frugality. A blast down a B-road will push this figure even lower.

Hybrid Efficiency

Toyota’s hybrid range, including the Prius and Yaris Hybrid, can achieve 60-70 MPG (4.0-4.7 L/100km) in real-world conditions. The electric motor assists during acceleration and low-speed driving, where petrol engines are least efficient.

Related Conversions

Fuel consumption links to other automotive measurements you might need to convert.

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