Fuel Economy Converter

Convert MPG (US), MPG (UK), L/100km, km/L, and more

💡 Tip: Press Ctrl+D for dark mode, Ctrl+K to focus converter

⛽ Fuel Economy Converter

Convert between MPG, L/100km, km/L, and more

💡 Quick Tip: 30 MPG (US) ≈ 7.84 L/100km | Lower L/100km = Better efficiency
30 MPG (US) = 7.84 L/100km

Fuel Economy Conversion Guide

Common Fuel Economy Conversions

MPG (US) MPG (UK) L/100km km/L
20 24.0 11.76 8.50
25 30.0 9.41 10.63
30 36.0 7.84 12.75
35 42.0 6.72 14.88
40 48.0 5.88 17.00
45 54.0 5.23 19.13
50 60.0 4.70 21.25
60 72.0 3.92 25.50
70 84.1 3.36 29.75

Understanding Fuel Economy Units

Distance per Volume (Higher is Better)

MPG (US) - Miles Per Gallon (US) - How many miles you can drive on one US gallon (3.785 liters). Standard in the United States. Higher MPG = better fuel economy.

MPG (UK) - Miles Per Gallon (Imperial) - Uses UK Imperial gallon (4.546 liters), which is 20% larger than US gallon. UK MPG is always about 20% higher than US MPG for the same vehicle.

km/L - Kilometers Per Liter - How many kilometers you can drive on one liter of fuel. Common in Asia and parts of South America. Higher km/L = better fuel economy.

Miles per Liter - Less common but useful for comparing imperial distances with metric fuel volumes.

Volume per Distance (Lower is Better)

L/100km - Liters Per 100 Kilometers - How many liters of fuel needed to drive 100 kilometers. Standard in Europe, Australia, Canada, and most of the world. Lower L/100km = better fuel economy (opposite of MPG!).

Key Difference: MPG vs L/100km

CRITICAL UNDERSTANDING:

  • 📊 MPG (higher is better): 50 MPG is more efficient than 25 MPG
  • 📊 L/100km (lower is better): 5 L/100km is more efficient than 10 L/100km
  • 🔄 They're inverses: Higher MPG = Lower L/100km
  • 💡 Why L/100km? Makes it easier to calculate fuel cost for a trip

Practical Fuel Economy Examples

  • 🚙 Economy Car (Honda Civic): 35 MPG (US) = 6.72 L/100km
  • 🚗 Mid-size Sedan (Toyota Camry): 32 MPG (US) = 7.35 L/100km
  • 🚙 Compact SUV (Honda CR-V): 30 MPG (US) = 7.84 L/100km
  • 🚐 Full-size SUV (Ford Expedition): 20 MPG (US) = 11.76 L/100km
  • 🚚 Pickup Truck (Ford F-150): 22 MPG (US) = 10.69 L/100km
  • 🏎️ Sports Car (Corvette): 25 MPG (US) = 9.41 L/100km
  • ⚡ Hybrid (Toyota Prius): 55 MPG (US) = 4.28 L/100km
  • 🔌 Plug-in Hybrid: 60+ MPG (US) = 3.92 L/100km (gas only)
  • 🚛 Semi Truck: 6-8 MPG (US) = 29-39 L/100km
  • 🏍️ Motorcycle: 50-60 MPG (US) = 3.92-4.70 L/100km

Why Different Fuel Economy Units?

Different measurement systems evolved in different regions:

  • 🇺🇸 MPG (US): United States - imperial system (miles, gallons)
  • 🇬🇧 MPG (UK): United Kingdom - imperial miles, larger imperial gallon
  • 🌍 L/100km: Most of the world - metric system, easier trip calculations
  • 🌏 km/L: Popular in Asia - metric but similar concept to MPG

Fuel Economy Conversion Formulas

MPG (US) to L/100km:

L/100km = 235.215 ÷ MPG (US)

L/100km to MPG (US):

MPG (US) = 235.215 ÷ L/100km

MPG (US) to MPG (UK):

MPG (UK) = MPG (US) × 1.20095

MPG (UK) to MPG (US):

MPG (US) = MPG (UK) ÷ 1.20095

MPG (US) to km/L:

km/L = MPG (US) × 0.425144

km/L to MPG (US):

MPG (US) = km/L × 2.35215

Quick Mental Math Tips

MPG to L/100km (rough estimate):

  • Divide 240 by MPG → Example: 240 ÷ 30 = 8 L/100km (actual: 7.84)
  • Remember: Higher MPG = Lower L/100km

L/100km to MPG (rough estimate):

  • Divide 240 by L/100km → Example: 240 ÷ 8 = 30 MPG (actual: 29.4)

US MPG to UK MPG:

  • Add 20% → Example: 30 US MPG × 1.2 = 36 UK MPG ✓

Quick conversions to remember:

  • 30 MPG (US) ≈ 8 L/100km ≈ 12.5 km/L
  • 50 MPG (US) ≈ 5 L/100km ≈ 20 km/L

Calculating Fuel Costs

Using MPG (US):

Cost = (Miles ÷ MPG) × Price per gallon
Example: (300 miles ÷ 30 MPG) × $3.50 = $35

Using L/100km:

Cost = (km ÷ 100) × L/100km × Price per liter
Example: (500 km ÷ 100) × 8 L/100km × $1.50 = $60

Fuel Economy by Vehicle Type

Vehicle Type Typical MPG (US) Typical L/100km
Compact Car 32-38 6.2-7.4
Mid-size Car 28-34 6.9-8.4
Large Car 24-30 7.8-9.8
Small SUV 28-32 7.4-8.4
Mid-size SUV 22-28 8.4-10.7
Large SUV 16-22 10.7-14.7
Pickup Truck 18-24 9.8-13.1
Minivan 22-28 8.4-10.7
Hybrid Car 45-55 4.3-5.2
Sports Car 20-28 8.4-11.8

Factors Affecting Fuel Economy

  • 🚗 Driving style: Aggressive driving can reduce MPG by 15-30%
  • 🏔️ Terrain: Hills and mountains decrease fuel economy
  • 🌡️ Weather: Cold weather reduces MPG by 10-20%
  • ❄️ AC/Heat: Can reduce fuel economy by 5-25%
  • ⚖️ Weight: Every 100 lbs reduces MPG by ~1%
  • 💨 Speed: Efficiency drops significantly above 50 mph
  • 🛞 Tire pressure: Under-inflated tires can reduce MPG by 3%
  • 🚦 City vs Highway: Highway typically gets 25-35% better MPG

Tips to Improve Fuel Economy

  • 🐌 Drive smoothly: Avoid rapid acceleration and braking
  • ⚡ Maintain speed: Use cruise control on highways
  • 🛞 Check tire pressure: Keep at recommended PSI
  • 🏋️ Remove excess weight: Clear trunk of unnecessary items
  • 🪟 Windows vs AC: Above 50 mph, AC is more efficient
  • 🔧 Regular maintenance: Clean air filters, tune-ups
  • 🚗 Combine trips: Cold starts use more fuel
  • 📍 Plan routes: Avoid traffic and minimize idling

US vs UK Gallon Explained

Why the difference?

  • 📏 US Gallon: 3.785 liters (231 cubic inches)
  • 📏 UK Gallon: 4.546 liters (277.42 cubic inches)
  • 📊 Difference: UK gallon is 20% larger
  • 🚗 Example: Car gets 30 US MPG = 36 UK MPG (same efficiency)
  • ⚠️ Confusion: Always specify US or UK when using MPG!

Frequently Asked Questions

How do I convert MPG to L/100km?

Divide 235.215 by the US MPG value. For example, 235.215 ÷ 30 MPG = 7.84 L/100km. Remember: higher MPG means lower L/100km (more efficient).

What is the difference between US MPG and UK MPG?

US and UK gallons are different sizes. US gallon = 3.785 liters, UK gallon = 4.546 liters (20% larger). So UK MPG is about 20% higher than US MPG for the same vehicle. Always specify which gallon when using MPG!

What does L/100km mean?

L/100km (liters per 100 kilometers) measures how many liters of fuel you need to drive 100 km. It's the standard metric fuel consumption unit. Lower is better - 5 L/100km is more efficient than 10 L/100km.

How do I convert km/L to MPG?

Multiply km/L by 2.352 to get US MPG, or by 2.825 to get UK MPG. For example, 15 km/L × 2.352 = 35.3 US MPG.

Why does Europe use L/100km instead of MPG?

L/100km makes trip fuel calculations easier. Example: 500 km trip at 8 L/100km = (500÷100) × 8 = 40 liters needed. It's also metric, matching Europe's distance and volume measurements.

What is good fuel economy?

For gasoline cars: 30+ MPG (US) or under 8 L/100km is considered good. 40+ MPG (6 L/100km) is excellent. Hybrids can achieve 50+ MPG (under 5 L/100km). Electric vehicles don't use these measurements.

How accurate is this fuel economy converter?

Our converter uses exact conversion factors from international standards. Results are accurate up to 10 decimal places, far exceeding practical needs for fuel economy calculations.

Quick Reference Chart

Common Conversions:

  • 20 MPG (US) = 24.0 MPG (UK) = 11.76 L/100km = 8.5 km/L
  • 30 MPG (US) = 36.0 MPG (UK) = 7.84 L/100km = 12.8 km/L
  • 40 MPG (US) = 48.0 MPG (UK) = 5.88 L/100km = 17.0 km/L
  • 50 MPG (US) = 60.1 MPG (UK) = 4.70 L/100km = 21.3 km/L

Gallon Sizes:

  • 1 US gallon = 3.785 liters = 0.833 UK gallons
  • 1 UK gallon = 4.546 liters = 1.201 US gallons

Rule of Thumb:

  • Divide 235 by MPG (US) ≈ L/100km
  • Divide 235 by L/100km ≈ MPG (US)
  • UK MPG = US MPG × 1.2