How do I calculate the fuel cost for a trip?

For metric units: Fuel needed (litres) = Distance (km) x Consumption (L/100km) / 100. Then multiply by the fuel price per litre to get total cost. For imperial units: Fuel needed (gallons) = Distance (miles) / MPG. Then multiply by the price per gallon. For example, a 500 km trip at 8 L/100km with fuel at $1.80/L needs 40 litres and costs $72.

What is a good fuel consumption rate?

Fuel consumption varies by vehicle type. A small city car typically uses 5-7 L/100km (34-47 MPG). A mid-size sedan uses 7-10 L/100km (24-34 MPG). An SUV uses 10-14 L/100km (17-24 MPG). Hybrid vehicles can achieve 3-5 L/100km (47-78 MPG). Electric vehicles use no petrol or diesel at all.

How do I convert between L/100km and MPG?

To convert L/100km to US MPG: MPG = 235.215 / (L/100km). To convert US MPG to L/100km: L/100km = 235.215 / MPG. For example, 8 L/100km equals approximately 29.4 MPG, and 30 MPG equals approximately 7.84 L/100km. For UK (imperial) MPG, use 282.481 instead of 235.215.

How much does it cost to drive per kilometre?

Cost per kilometre = Consumption (L/100km) x Fuel price per litre / 100. For a car using 8 L/100km with fuel at $1.80/L: 8 x 1.80 / 100 = $0.144 per km. For imperial: Cost per mile = Fuel price per gallon / MPG. At $3.50/gallon and 30 MPG: 3.50 / 30 = $0.117 per mile.

How can I reduce my fuel costs?

Maintain steady speeds and avoid aggressive acceleration. Keep tyres properly inflated (under-inflation increases consumption by 3-5%). Remove unnecessary weight and roof racks. Use cruise control on highways. Plan routes to avoid congestion. Service your vehicle regularly. Consider a more fuel-efficient vehicle for your next purchase — use the Compare Vehicles tab to see the savings.

Fuel Cost Calculator

How much will fuel cost for your trip? Calculate trip fuel expenses, compare two vehicles side by side, or estimate your annual fuel spending.

Currency

All amounts displayed in selected currency

Trip distance

One-way or round-trip distance

Unit system

Switches distance and consumption units

Fuel consumption (L/100km)

Litres per 100 kilometres

Fuel price per L

Current price at the pump

Fuel unit

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Estimates only. Actual fuel consumption varies with driving conditions. Not financial advice.

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How to Use This Calculator

Tab "Trip Cost"

Enter your trip distance, choose metric or imperial units, enter your vehicle's fuel consumption (L/100km or MPG), and the current fuel price per litre or gallon. The calculator instantly shows total fuel needed, trip cost, and cost per kilometre or mile.

Tab "Compare Vehicles"

Enter the same trip distance and fuel price, then input the fuel consumption for two different vehicles. The calculator shows fuel needed and cost for each vehicle, the savings per trip, and the annual savings if you drive 15,000 km/yr (or 9,320 mi/yr). Useful when deciding between an SUV and a sedan, or comparing a hybrid against a petrol car.

Tab "Annual Fuel Cost"

Enter your annual driving distance, average fuel consumption, and average fuel price. The result shows your total annual fuel expenditure, monthly average, and cost per distance unit. Great for budgeting your yearly transport costs.

The Formulas

Metric (L/100km):
Fuel needed (L) = Distance (km) × Consumption (L/100km) / 100
Total cost = Fuel needed × Price per litre
Cost per km = Consumption × Price / 100

Imperial (MPG):
Fuel needed (gal) = Distance (miles) / MPG
Total cost = Fuel needed × Price per gallon
Cost per mile = Price per gallon / MPG

Annual fuel cost:
Annual fuel = Annual distance × Consumption / 100 (metric) or Annual distance / MPG (imperial)
Annual cost = Annual fuel × Price per unit
Monthly average = Annual cost / 12

All calculations use standard fuel consumption mathematics. No country-specific fuel prices or tax rates are applied automatically — enter your local values.

Worked Examples

Example 1 — City trip: 500 km at 8 L/100km, fuel at €1.80/L

A driver plans a 500 km road trip in a mid-size sedan that consumes 8 litres per 100 km. Fuel costs €1.80 per litre.

Distance500 km

Consumption8 L/100km

Fuel needed = 500 × 8 / 10040 L

Fuel price€1.80/L

Total cost = 40 × €1.80€72.00

Cost per km = 8 × 1.80 / 100€0.144/km

The 500 km trip costs €72.00 in fuel. For a round trip (1,000 km), double it to €144.00.

Example 2 — SUV vs Sedan: 500 km, 12 vs 7 L/100km, fuel at €1.80/L

Comparing an SUV (12 L/100km) against a compact sedan (7 L/100km) for the same 500 km trip.

Metric	SUV (12 L/100km)	Sedan (7 L/100km)
Fuel needed	60 L	35 L
Trip cost	€108.00	€63.00
Cost per km	€0.216	€0.126
Trip savings	€45.00 (sedan saves 42%)

Over 15,000 km/year, the sedan saves €1,350 in fuel annually compared to the SUV. That is €112.50 per month — enough to cover a car insurance premium in many countries.

Example 3 — Annual commute: 20,000 km at 9 L/100km, fuel at €1.75/L

A daily commuter drives 20,000 km per year in a car consuming 9 L/100km with an average fuel price of €1.75/L.

Annual distance20,000 km

Consumption9 L/100km

Annual fuel = 20,000 × 9 / 1001,800 L

Fuel price€1.75/L

Annual cost = 1,800 × €1.75€3,150.00

Monthly average = €3,150 / 12€262.50

Cost per km€0.1575

The commuter spends €3,150 on fuel per year, or €262.50 per month. Reducing consumption by just 1 L/100km (to 8 L/100km) would save €350 annually.

Understanding Fuel Costs: Key Concepts

L/100km vs MPG

Most of the world uses litres per 100 kilometres (L/100km) where a lower number means better efficiency. The United States uses miles per gallon (MPG) where a higher number is better. The UK uses imperial MPG (larger gallons), which gives higher numbers than US MPG for the same vehicle. This calculator supports both metric and US imperial systems.

Factors That Affect Fuel Consumption

Your actual consumption depends on driving style (aggressive acceleration increases fuel use by 15-30%), speed (fuel efficiency drops significantly above 100 km/h or 60 mph), traffic conditions (city driving uses 30-50% more fuel than highway), vehicle load, tyre pressure, and weather (cold weather and headwinds increase consumption).

How Fuel Prices Vary

Fuel prices differ dramatically by country due to varying tax rates, subsidies, and refining costs. European countries typically have higher prices due to fuel duty, while some Middle Eastern and Asian countries subsidise fuel. Prices also fluctuate with crude oil markets, seasonal demand, and local competition between stations.

Frequently Asked Questions

How do I calculate fuel cost for a road trip?▼

Divide your trip distance by 100 and multiply by your car's consumption rate (L/100km) to get litres needed. Multiply litres by the price per litre to get total cost. For example: 800 km trip, 9 L/100km consumption, fuel at €1.85/L = 800 × 9 / 100 = 72 litres × €1.85 = €133.20. For MPG: divide distance by MPG to get gallons, then multiply by price per gallon.

Where do I find my car's fuel consumption?▼

Check your car's owner's manual, the sticker on the driver's door jamb, or the manufacturer's website. Many modern cars also display real-time and average consumption on the dashboard trip computer. For the most accurate figure, fill up your tank, drive until you need to refuel, fill up again, and divide the litres (or gallons) pumped by the distance driven. Repeat 2-3 times for a reliable average.

Is the manufacturer's fuel consumption figure accurate?▼

Manufacturer figures are based on standardised lab tests (WLTP in Europe, EPA in the US) that do not perfectly replicate real driving. Real-world consumption is typically 10-25% higher than the official combined figure. City-only driving can be 30-50% higher. Use the official figure as a baseline and add 15-20% for a more realistic estimate, or measure your own consumption as described above.

How do I convert L/100km to MPG?▼

For US MPG: divide 235.215 by the L/100km value. For example, 8 L/100km = 235.215 / 8 = 29.4 MPG. For UK (imperial) MPG: divide 282.481 by L/100km. So 8 L/100km = 282.481 / 8 = 35.3 UK MPG. The difference is because a UK gallon (4.546 L) is larger than a US gallon (3.785 L).

How much can I save by switching to a more efficient car?▼

Use the Compare Vehicles tab to see exact savings. As a rough guide: reducing consumption by 3 L/100km (e.g., from 10 to 7) on 15,000 km/year at €1.80/L saves €810 per year. Over 5 years that is €4,050 — which can offset a significant portion of the price difference between vehicles. Hybrid and electric vehicles offer even larger savings on fuel, though they may have higher purchase prices.

Does this calculator work for diesel and petrol?▼

Yes. The formulas are identical for petrol (gasoline), diesel, LPG, and any other liquid fuel. Simply enter the correct consumption rate for your fuel type and the current price per litre or gallon for that fuel. Diesel vehicles typically have lower L/100km figures than equivalent petrol models, but diesel fuel may cost more or less per litre depending on your country.

Does this calculator include tolls and other driving costs?▼

No — this calculator covers fuel costs only. Total trip costs also include tolls, parking, vehicle wear (tyres, oil, brakes), depreciation, and insurance. Fuel typically represents 30-50% of total per-kilometre driving costs. For a complete picture, add tolls and parking to the fuel cost shown here.

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