Fuel Consumption / mpg (US) → mpg (imp)
Convert Miles per US liquid gallon to Miles per imperial gallon
Convert vehicle fuel use and fuel economy with reciprocal formulas. Convert Miles per US liquid gallon (mpg (US)) to Miles per imperial gallon (mpg (imp)). Find the formula, worked examples, unit definitions, and practical guidance below.
Reverse: Miles per imperial gallon to Miles per US liquid gallon →
How to convert Miles per US liquid gallon to miles per imperial gallon
Consumption measures fuel per distance; economy measures distance per fuel. Their relationship is reciprocal. US and imperial mpg use different gallons. Inputs must be positive; zero fuel use would imply infinite economy.
Use x for the value in mpg (US), b for the intermediate value in L/100 km, and y for the result in mpg (imp).
b = 235.214583333 ÷ x; y = 282.480936332 ÷ b
Worked examples
10 mpg (US) ≈ 12.009499255 mpg (imp)
Step 1: 235.214583333 ÷ 10 ≈ 23.5214583333 L/100 km.
Step 2: 282.480936332 ÷ 23.5214583333 ≈ 12.009499255 mpg (imp).20 mpg (US) ≈ 24.0189985101 mpg (imp)
Step 1: 235.214583333 ÷ 20 ≈ 11.7607291667 L/100 km.
Step 2: 282.480936332 ÷ 11.7607291667 ≈ 24.0189985101 mpg (imp).
Results are rounded to 12 significant digits. Converting units does not increase the precision of the original measurement. Very large or small values outside JavaScript’s finite numeric range are rejected.
About Miles per US liquid gallon
Miles per US liquid gallon relates inversely to Liters per 100 kilometers. The base value is 235.214583333 ÷ x, where x is the numerical value in mpg (US). A zero or negative reciprocal input is outside this calculator’s physical domain.
About Miles per imperial gallon
Miles per imperial gallon relates inversely to Liters per 100 kilometers. The base value is 282.480936332 ÷ x, where x is the numerical value in mpg (imp). A zero or negative reciprocal input is outside this calculator’s physical domain.
Definitions and sources
Carry the same physical assumptions into subsequent physics calculations.
Miles per US liquid gallon to miles per imperial gallon reference table
| Miles per US liquid gallon (mpg (US)) | Miles per imperial gallon (mpg (imp)) |
|---|---|
| 1 | 1.2009499255 |
| 5 | 6.00474962752 |
| 10 | 12.009499255 |
| 25 | 30.0237481376 |
| 50 | 60.0474962752 |
| 100 | 120.09499255 |
| 1000 | 1200.9499255 |
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