Gallon (US)/100mi to Miles/Gallon (UK) Converter

Fuel Economy Converter

11 units available

Decimals:

From

To

664.43663

1 gal/100mi = 664.43663 mpg (UK)

Formula:

mpg (UK) = gal/100mi × 664.4366303531

With your value: 1 gal/100mi = 664.43663035 mpg (UK)

Other Gallon (US)/100mi to Miles/Gallon (UK) conversions

2 gal/100mi to mpg (UK)3 gal/100mi to mpg (UK)4 gal/100mi to mpg (UK)5 gal/100mi to mpg (UK)6 gal/100mi to mpg (UK)7 gal/100mi to mpg (UK)8 gal/100mi to mpg (UK)

Gallon (US)/100mi to Miles/Gallon (UK) Conversion Table

Gallon (US)/100mi (gal/100mi)	Miles/Gallon (UK) (mpg (UK))
0.5	1,328.873261
1	664.43663
2	332.218315
5	132.887326
10	66.443663
15	44.295775
20	33.221832
25	26.577465
50	13.288733
100	6.644366
250	2.657747
500	1.328873
1000	0.664437

Miles/Gallon (UK) to Gallon (US)/100mi Conversion Table

Miles/Gallon (UK) (mpg (UK))	Gallon (US)/100mi (gal/100mi)
0.5	1,328.873261
1	664.43663
2	332.218315
5	132.887326
10	66.443663
15	44.295775
20	33.221832
25	26.577465
50	13.288733
100	6.644366
250	2.657747
500	1.328873
1000	0.664437

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Gallon (US)/100mi (gal/100mi)

Fuel Economy

Exact conversion

Composite of a defined volume and a defined length. US and imperial gallons differ, so mpg figures are not interchangeable between them.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

Miles/Gallon (UK) (mpg (UK))

Fuel Economy

Exact conversion

Composite of a defined volume and a defined length. US and imperial gallons differ, so mpg figures are not interchangeable between them.

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert Gallon (US)/100mi to Miles/Gallon (UK)

This conversion uses an offset formula, so it cannot be described by a single multiplication factor.

Formula: mpg (UK) = gal/100mi × 664.4366303531

Reverse: gal/100mi = mpg (UK) × 664.4366303531

Step-by-Step Example

Start with your value in Gallon (US)/100mi. For example: 5 gal/100mi
Apply mpg (UK) = gal/100mi × 664.4366303531
The result is: 132.887326 mpg (UK)

About Gallon (US)/100mi

The gallon (us)/100mi (gal/100mi) is a unit of fuel economy. The gallon (us)/100mi scale is offset from the kilometre per litre scale, so converting it requires both a factor and an offset rather than a single multiplier. UnitConvertLab converts it against every other fuel economy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: fuel economy calculations, engineering and science, education.

About Miles/Gallon (UK)

The miles/gallon (uk) (mpg (UK)) is a unit of fuel economy. One miles/gallon (uk) equals 0.354006044 kilometre per litres. UnitConvertLab converts it against every other fuel economy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: fuel economy calculations, engineering and science, education.

Frequently Asked Questions

How many Miles/Gallon (UK) are in 1 Gallon (US)/100mi?

There are exactly 664.4366303531 Miles/Gallon (UK) in 1 Gallon (US)/100mi.

What is the formula to convert Gallon (US)/100mi to Miles/Gallon (UK)?

The formula to convert Gallon (US)/100mi to Miles/Gallon (UK) is: mpg (UK) = gal/100mi × 664.4366303531. For example, to convert 10 Gallon (US)/100mi to Miles/Gallon (UK), you would apply the formula to 10.

What is a Gallon (US)/100mi?