100 US MPG to UK MPG
| 100 MPG (US) | = | 120.1 MPG (UK / Imperial) |
| 100 MPG (US) | = | 2.35 L/100km |
| 100 MPG (US) | = | 42.5 km/L |
How to Convert US MPG to UK MPG
The conversion is linear — the difference is entirely in the size of the gallon, not in the miles.
- MPG (UK) = MPG (US) × 1.20095042
The factor 1.20095 is the exact ratio between the Imperial gallon (4.54609 L) and the US gallon (3.785411784 L).
Applying the formula to 100 MPG (US): 100 × 1.20095 = 120.1 MPG (UK).
Is 100 MPG (US) good?
100 MPG (US) is considered Excellent — typical of hybrid and plug-in hybrid vehicles. In Imperial terms, that’s 120.1 MPG (UK). In metric terms, 2.35 L/100km or 42.5 km/L.
Need a different value? Use our US MPG to UK MPG Converter.
Similar Conversions
| MPG (US) | MPG (UK) | L/100km |
|---|---|---|
| 55 MPG | 66.1 | 4.28 |
| 60 MPG | 72.1 | 3.92 |
| 65 MPG | 78.1 | 3.62 |
| 70 MPG | 84.1 | 3.36 |
| 80 MPG | 96.1 | 2.94 |
Related Fuel Economy Converters
Conversion factors verified against NIST, BIPM
Based on SI definitions (BIPM).
Last reviewed: March 2026
