Fuel Cost Calculator
Calculate fuel costs for your journey based on distance, fuel efficiency, and current fuel prices.
Everyday Calculators
Understanding Fuel Cost Calculations
How Fuel Costs Are Calculated
Calculating fuel costs involves understanding the relationship between distance traveled, vehicle fuel efficiency, and fuel prices. The calculation may appear simple, but involves various unit conversions and depends on your measurement system.
Basic Fuel Cost Formula
The fundamental formula is:
Fuel Cost = Fuel Needed × Fuel Price per Unit
Fuel Needed = Distance ÷ Fuel Efficiency
However, the calculation differs based on your measurement system:
Metric System (L/100km)
In the metric system, fuel efficiency is typically expressed as liters per 100 kilometers (L/100km).
Fuel Needed (L) = (Distance (km) ÷ 100) × Efficiency (L/100km)
Imperial/US System (MPG)
In the Imperial or US system, fuel efficiency is typically expressed as miles per gallon (MPG).
Fuel Needed (gal) = Distance (miles) ÷ Efficiency (mpg)
Unit Conversion Factors
Distance Conversions
- 1 mile = 1.60934 kilometers
- 1 kilometer = 0.621371 miles
Volume Conversions
- 1 US gallon = 3.78541 liters
- 1 Imperial gallon = 4.54609 liters
- 1 liter = 0.264172 US gallons
Efficiency Conversions
- To convert from L/100km to MPG (US): MPG = 235.215 ÷ (L/100km)
- To convert from MPG (US) to L/100km: L/100km = 235.215 ÷ MPG
- To convert from MPG (Imperial) to L/100km: L/100km = 282.481 ÷ MPG
Example Calculations
Metric Example
Input:
- Distance: 300 kilometers
- Fuel efficiency: 8 L/100km
- Fuel price: $1.50 per liter
Calculation:
Fuel needed = (300 ÷ 100) × 8 = 3 × 8 = 24 liters
Total cost = 24 × $1.50 = $36.00
Imperial/US Example
Input:
- Distance: 200 miles
- Fuel efficiency: 25 mpg
- Fuel price: $3.50 per gallon
Calculation:
Fuel needed = 200 ÷ 25 = 8 gallons
Total cost = 8 × $3.50 = $28.00
Factors Affecting Fuel Consumption
Vehicle Factors
- Engine size and type
- Vehicle weight
- Aerodynamics
- Transmission type
- Age and maintenance
- Tire pressure and type
- Air conditioning use
Driving Patterns
- Aggressive acceleration
- Excessive braking
- Speed (higher speeds = increased air resistance)
- Idling time
- Highway vs. city driving
- Cold starts
- Traffic conditions
Environmental Factors
- Road conditions
- Terrain (hills vs. flat roads)
- Weather conditions
- Wind resistance
- Temperature extremes
- Altitude
- Fuel quality and type
Improving Fuel Efficiency
Vehicle Maintenance
- Regular Tune-ups: An engine that's properly tuned can improve fuel efficiency by up to 4%.
- Proper Tire Inflation: Keeping tires inflated to the proper pressure can improve gas mileage by up to 3%.
- Use Recommended Oil Grade: Using the manufacturer's recommended grade of motor oil can improve fuel economy by 1-2%.
- Replace Air Filters: A clogged air filter can reduce fuel economy by up to 10% in older vehicles.
- Fix Mechanical Issues Promptly: A faulty oxygen sensor, for example, can decrease fuel efficiency by up to 40%.
Driving Habits
- Drive Smoothly: Avoid rapid acceleration and braking, which can lower gas mileage by 15-30% at highway speeds.
- Observe Speed Limits: Gas mileage decreases rapidly at speeds above 50 mph. Each 5 mph over 50 is like paying an additional $0.15-$0.30 per gallon.
- Reduce Idling: Idling can use a quarter to a half gallon of fuel per hour, depending on engine size and air conditioner use.
- Use Cruise Control: On highways, maintaining a constant speed with cruise control can save fuel.
- Plan and Combine Trips: Several short trips taken from a cold start can use twice as much fuel as a longer trip covering the same distance.
Understanding Fuel Economy Metrics
L/100km vs. MPG
These metrics are reciprocal - they measure the same thing but from opposite perspectives:
- L/100km (Metric) measures consumption - how much fuel is used to travel a fixed distance.
- MPG (Imperial/US) measures efficiency - how far you can travel on a fixed amount of fuel.
A lower L/100km or a higher MPG both indicate better fuel economy.
Important note: The relationship between these metrics is not linear. A 1 MPG improvement at low efficiency (e.g., from 15 to 16 MPG) saves significantly more fuel than a 1 MPG improvement at high efficiency (e.g., from 45 to 46 MPG).
Common Efficiency Ratings
| Vehicle Type | L/100km (approx.) | MPG (approx.) |
|---|---|---|
| Compact Car | 6-8 | 30-40 |
| Midsize Sedan | 8-10 | 24-30 |
| SUV | 10-14 | 17-24 |
| Pickup Truck | 12-18 | 13-20 |
| Hybrid Vehicle | 4-6 | 40-60 |
| Electric Vehicle* | 2-3 (equivalent) | 80-130 (equivalent) |
*Electric vehicles use kWh/100km or MPGe metrics
Trip Planning and Cost Sharing
When planning road trips with multiple people, consider these approaches for equitable cost sharing:
Equal Split Method
- Best for: Friends or colleagues sharing equal space and baggage
- How it works: Total fuel cost divided equally among all passengers
- Advantage: Simple calculation and fair when everyone travels the same route
Driver Pays Less Method
- Best for: When one person provides the vehicle and does all driving
- How it works: Driver pays a smaller percentage (e.g., 10-25% less) than passengers
- Advantage: Acknowledges driver's additional contribution and responsibility
For maximum transparency, our calculator shows both the total trip cost and per-person breakdowns. This makes it easy to split costs fairly regardless of which approach you choose.
Environmental Considerations
Carbon Emissions
Each liter of gasoline burned produces approximately 2.3 kg of CO₂. For diesel, it's about 2.7 kg per liter. Carpooling and choosing fuel-efficient vehicles can significantly reduce your carbon footprint.
Alternative Transport
For some journeys, consider alternatives like trains, buses, or carpooling. These options often have lower per-person emissions and can be more cost-effective for certain routes.
Route Optimization
The shortest route isn't always the most fuel-efficient. Modern navigation apps can suggest routes that minimize fuel consumption by avoiding steep hills, congestion, and excessive stopping.
Electric Vehicle Considerations
If you drive an electric vehicle (EV), the calculation changes from fuel cost to electricity cost:
EV Cost Calculation Formula:
Cost = Distance × Energy Consumption × Electricity Rate
- Distance in km or miles
- Energy Consumption in kWh per km or kWh per mile
- Electricity Rate in cost per kWh
Example: For a 300 km trip in an EV that consumes 0.18 kWh/km with electricity costing $0.15/kWh:
Cost = 300 × 0.18 × $0.15 = $8.10
This is significantly lower than equivalent gasoline costs, highlighting one of the economic benefits of electric vehicles despite their typically higher purchase price.