US Miles Per Gallon to Liters Per 100 Km
30 US miles per gallon equals 7.84 liters per 100 km. The two run in opposite directions, so a higher figure on one side is a lower figure on the other.
L/100km = 235.2145833 ÷ MPG (US)
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Understanding Fuel Economy Units
MPG (Miles per Gallon): Distance traveled per unit of fuel
L/100km: Fuel consumed per 100 kilometers (lower is better)
km/L: Distance per liter (higher is better)
US vs UK Gallons: US gallon = 3.785L, UK gallon = 4.546L
Inverse Relationship: Higher MPG = Lower L/100km
Global Standards: Most countries use L/100km
Fuel Efficiency Categories
Excellent: 40+ MPG (5.9 L/100km or less)
Good: 30-39 MPG (6.0-7.8 L/100km)
Average: 20-29 MPG (8.1-11.8 L/100km)
Below Average: 15-19 MPG (12.4-15.7 L/100km)
Poor: Under 15 MPG (over 15.7 L/100km)
Hybrid/Electric: 50+ MPG equivalent
Conversion Quick Reference
• 30 MPG (US) ≈ 7.84 L/100km ≈ 12.75 km/L
• 40 MPG (US) ≈ 5.88 L/100km ≈ 17.01 km/L
• 50 MPG (US) ≈ 4.70 L/100km ≈ 21.26 km/L
• 6 L/100km ≈ 39.2 MPG (US) ≈ 16.67 km/L
US Miles Per Gallon to Liters Per 100 Km Conversion Table
| MPG (US) | L/100km |
|---|---|
| 10 | 23.5215 |
| 15 | 15.681 |
| 20 | 11.7607 |
| 25 | 9.4086 |
| 30 | 7.8405 |
| 35 | 6.7204 |
| 40 | 5.8804 |
| 45 | 5.227 |
| 50 | 4.7043 |
| 55 | 4.2766 |
| 60 | 3.9202 |
| 70 | 3.3602 |
| 80 | 2.9402 |
| 100 | 2.3521 |
About This Conversion
US miles per gallon to liters per 100 km is the conversion between the two ways the world states fuel economy, and the one place a converter genuinely earns its keep, because the relationship inverts. MPG counts distance per fuel, so higher is better; L/100km counts fuel per distance, so lower is better.
Because it is a division rather than a multiplication, equal steps in MPG are not equal steps in fuel use. Going from 15 to 20 MPG saves 3.9 L/100km; going from 40 to 45 saves only 0.65. That is why efficiency gains at the thirsty end of the range matter far more than the same gain on an already economical car.
Frequently Asked Questions
What is 30 MPG in L/100km?
30 US MPG is 7.84 L/100km.
What is the formula?
Divide 235.2145833 by the US MPG figure. The constant is 100 × 3.785411784 ÷ 1.609344.
Is a lower L/100km better?
Yes. L/100km measures fuel used over a fixed distance, so a smaller number means a more efficient car.
Why can I not just multiply?
The two units are inverses. One is distance per fuel and the other fuel per distance, so the conversion is a division.
Worth Knowing
US Gallon vs Imperial Gallon
A US gallon is 3.785411784 litres and an imperial (UK) gallon is 4.54609 litres, making the imperial gallon about 20.1 percent larger.
Related Conversions
Converting the other way? Liters Per 100 Km to US Miles Per Gallon
Need a different unit? Open the full fuel economy converter