Fuel Cost Calculator

Estimate fuel cost for a trip based on distance, fuel efficiency, and gas price. Supports miles, kilometers, mpg, km/L, and L/100km.

How to Calculate Fuel Cost

The formula is straightforward:

Fuel Cost = (Distance ÷ Fuel Efficiency) × Fuel Price

For a 500-mile trip at 25 mpg with gas at $3/gallon: 500 ÷ 25 = 20 gallons × $3 = $60.

Unit Support

Distance: miles or kilometers
Efficiency: miles per gallon (mpg), kilometers per liter (km/L), or liters per 100 km (L/100km)
Fuel price: per gallon or per liter

Average Fuel Efficiency by Vehicle Type

Compact car: 28–35 mpg
Midsize sedan: 25–32 mpg
SUV: 20–28 mpg
Pickup truck: 15–22 mpg
Hybrid: 40–60 mpg
Electric (equivalent): 100+ mpge

Tips to Save on Fuel

Drive steadily: Aggressive acceleration and braking can reduce efficiency by 15–30%
Check tire pressure: Underinflated tires increase fuel consumption by 2–3%
Reduce speed: Each 5 mph over 50 mph costs roughly $0.15–$0.30 more per gallon
Minimize idling: Idling uses ¼ to ½ gallon per hour
Use cruise control: Maintains steady speed on highways, improving efficiency
Plan routes: Avoid traffic, combine errands, and use highway routes when possible

Fuel Efficiency Conversions

1 mpg = 0.4251 km/L
1 km/L = 2.352 mpg
To convert mpg to L/100km: 235.215 ÷ mpg
25 mpg = 10.6 km/L = 9.4 L/100km

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On conv.awajis.com

MPG to L/100km

Convert fuel economy figures.

Frequently Asked Questions

How is fuel cost calculated?

Divide the trip distance by fuel efficiency to get gallons (or liters) needed, then multiply by the fuel price. For example: 500 miles ÷ 25 mpg = 20 gallons × $3/gallon = $60.

What is a good fuel efficiency?

The US average is about 25 mpg. Hybrids get 40-60 mpg, EVs equivalent to 100+ mpge, and trucks/SUVs typically get 15-22 mpg.

How do I convert mpg to km/L?

Multiply mpg by 0.4251. For example, 25 mpg ≈ 10.6 km/L.

What does L/100km mean?

Liters per 100 kilometers — the metric fuel efficiency standard. Lower is better. 8 L/100km ≈ 29 mpg.

How can I reduce fuel costs?

Maintain steady speeds, keep tires inflated, reduce idling, remove excess weight, use cruise control on highways, and plan efficient routes.

How do I calculate fuel cost for a round trip?

Double the one-way distance before entering it. A 300-mile round trip at 28 mpg uses about 21.4 gallons total. Alternatively, run the calculator once for each leg and add the two costs.

Why does real-world fuel economy differ from the EPA rating?

EPA ratings come from controlled lab tests. Real-world efficiency drops due to speeds above 60 mph, cold temperatures, air conditioning, extra cargo weight, and stop-and-go traffic. Plan for 10 to 20 percent below the EPA figure on mixed driving.

How do I use L/100km efficiency in this calculator?

Select km as the distance unit and L/100km as the efficiency unit, then enter your vehicle efficiency value — a lower number means better economy. The calculator handles the conversion internally.