Convert

Miles per imperial gallon to Miles per US gallon

Exact answer: mpg US = mpg imp × 0.832674 (inverse relationship, not a linear factor)

Miles per imperial gallon and Miles per US gallon run in opposite directions. A higher value in one unit means a lower one in the other. Consumption figures appear in vehicle data, test reports and travel cost calculations.

Unit console

Convert units with formula, context and precision

UnitCloud is a local measurement lab for everyday work, engineering, IT, energy, mobility and design. Every conversion shows result, formula, base unit, rounding and the common mistake.

What do you want to convert?

From10 mpg imp

Result8.326742 mpg US

FactorInverse formula

Source basisNIST Guide to SI Appendix B

Examples

0110 mpg imp = 8.326742 mpg US

Example value from the reference table. Internal calculation uses stored factors; display output is rounded.

02Common mistake

mpg and l/100 km move in opposite directions. Higher mpg means lower consumption; higher l/100 km means higher consumption.

03Base unit: l/100 km

Fuel units are normalised through litres per 100 kilometres; mpg and km/l are inverse values.

Table

Miles per imperial gallon to Miles per US gallon
Miles per imperial gallon	Miles per US gallon
10	8.326742
20	16.653484
30	24.980226
40	33.306967
50	41.633709
80	66.613935

Formula

Fuel units are normalised through litres per 100 kilometres; mpg and km/l are inverse values.

Sources

NIST Guide to SI Appendix BNIST conversion-factor method and non-SI factors.

Related conversions

Miles per US gallon to Litres per 100 kilometresmpg US → l/100 kmFuel economy Litres per 100 kilometres to Miles per US gallonl/100 km → mpg USFuel economy Miles per imperial gallon to Litres per 100 kilometresmpg imp → l/100 kmFuel economy Litres per 100 kilometres to Miles per imperial gallonl/100 km → mpg impFuel economy

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Factor origin

Factors come from the stored source family and are not derived from rounded display values.

Rounding rule

UnitCloud keeps calculating with stored factors and rounds only the displayed output by selected precision.

When not to use

Do not use as the sole basis for official, medical, safety-critical or contractual decisions.

Citation

Citation note: UnitCloud, conversion with formula, sources reviewed: September 2026. Fuel economy. Source basis: NIST Guide to SI Appendix B.

Common questions

Which formula applies to Miles per imperial gallon to Miles per US gallon?

mpg US = mpg imp × 0.832674

Which formula does Miles per imperial gallon to Miles per US gallon use?

Fuel units are normalised through litres per 100 kilometres; mpg and km/l are inverse values.

What is the most common mistake?

mpg and l/100 km move in opposite directions. Higher mpg means lower consumption; higher l/100 km means higher consumption.

When should I verify the result?

Do not use as the sole basis for official, medical, safety-critical or contractual decisions.