When to use this calculator
Calculate fuel economy using imperial gallons and miles. Uses the UK imperial gallon, which differs from the US liquid gallon.
Explore the fuel use & cost calculators for other questions in this topic. For a related calculation, use the Miles Per Gallon US Calculator: Calculate fuel economy using US liquid gallons and miles.
PUTTING IT INTO PRACTICE
Miles Per Gallon UK: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Miles travelled | 300 |
| Fuel used (litres) | 30 |
| Result | 45.4609 UK mpg |
- Check the input labels and enter the example values above.
- Apply the relationship: Imperial MPG = miles × 4.54609 ÷ litres.
- The result is 45.4609 UK mpg, rounded for display.
How to interpret your result
Uses the UK imperial gallon, which differs from the US liquid gallon.
State the fuel-economy convention: UK imperial and US liquid gallons have different volumes. L/100 km is consumption, so lower values indicate less fuel used per distance. Input prices are scenario values.
Frequently asked questions
Are UK MPG and US MPG comparable without conversion?
No. Both use miles but different gallon volumes, so their numerical values differ for the same vehicle consumption.
How do I use the miles per gallon uk calculator?
Enter miles travelled, fuel used (litres). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Imperial MPG = miles × 4.54609 ÷ litres.
What should I check before using the result?
Uses the UK imperial gallon, which differs from the US liquid gallon.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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