Convert Miles per Imperial Gallon to Miles per US Gallon
Convert Miles per Imperial Gallon (mpg (Imp)) to Miles per US Gallon (mpg (US)) instantly and accurately.
Conversion Formula
mpg (US) = mpg (Imp) × 1.200949926
About Miles per Imperial Gallon
Miles per Imperial gallon (mpg(Imp)) is the UK and historically Commonwealth standard. The Imperial gallon (4.54609 L) is ~20.1% larger than the US gallon, so mpg(Imp) is always numerically higher: a 7 L/100km car achieves 33.6 mpg(US) but 40.4 mpg(Imp). All UK VCA-certified specs list mpg(Imp). Typical WLTP combined: supermini 45-60 mpg; full hybrid 55-75 mpg; diesel family car 48-68 mpg; large petrol SUV 28-38 mpg. 1 mpg(Imp) = 1.609344/4.54609 km/L = 0.354006 km/L; L/100km = 282.481/mpg(Imp).
About Miles per US Gallon
Miles per US gallon (mpg(US)) is the US and Canadian standard, displayed on every EPA Monroney sticker and used in CAFE regulations. The US gallon = 3.785411784 L; 1 mile = 1.609344 km. 2026 CAFE passenger car standard: ~49 mpg. Toyota Prius Prime: 52 mpg; Tesla Model 3: 132 MPGe. Historical: Ford Model T 21-25 mpg; 1973 US full-size cars 10-15 mpg. NASCAR at race speed: 4-5 mpg; Class 8 semi: 5-8 mpg. L/100km = 235.21458/mpg(US): 30 mpg = 7.84 L/100km; 50 mpg = 4.71 L/100km.
Quick Reference Table
| Miles per Imperial Gallon (mpg (Imp)) | Miles per US Gallon (mpg (US)) |
|---|---|
| 1 mpg (Imp) | 0.832674 mpg (US) |
| 2 mpg (Imp) | 1.66535 mpg (US) |
| 5 mpg (Imp) | 4.16337 mpg (US) |
| 10 mpg (Imp) | 8.32674 mpg (US) |
| 25 mpg (Imp) | 20.8169 mpg (US) |
| 50 mpg (Imp) | 41.6337 mpg (US) |
| 100 mpg (Imp) | 83.2674 mpg (US) |