Fuel Cost Calculator

Enter travel distance, fuel efficiency, and fuel price to instantly estimate your trip fuel cost. Plan travel and commute expenses with this free online fuel cost calculator.

How to Use

  1. Enter trip details

    Input the travel distance (km or miles) and your vehicle's fuel efficiency.

  2. Enter fuel price

    Input the current fuel price per liter or gallon.

  3. View results

    Click Calculate to see the fuel required and total trip cost.

What is fuel cost?

Fuel cost is the monetary cost of the fuel consumed to drive a given distance, determined by three variables: travel distance, vehicle fuel efficiency, and fuel price. Over the same distance, a more efficient vehicle uses less fuel and costs less, while a higher fuel price raises the cost proportionally.

Why calculate it in advance

  • Travel and business trip budgets: Estimate round-trip fuel costs before a long journey to plan your transport budget.
  • Commuting costs: Converting your monthly commute distance lets you compare the real cost of public transit versus driving.
  • Vehicle comparison: Looking at cost per km reveals how large a long-term spending gap a difference in fuel efficiency can create.

This calculator also estimates CO₂ emissions alongside the cost, helping you weigh economy and environmental impact at the same time.

Calculation formula

For a round trip, the distance is doubled first, then the calculation proceeds in this order.

Fuel needed (L) = Distance ÷ Fuel efficiency
Total fuel cost = Fuel needed × Fuel price
Cost per km = Total fuel cost ÷ Distance
CO₂ emissions (kg) = Fuel needed × 2.31

Example: distance 300 km, efficiency 12 km/L, fuel price 1,700 KRW/L, one way → fuel needed = 300 ÷ 12 = 25 L, total fuel cost = 25 × 1,700 = 42,500 KRW, cost per km = 42,500 ÷ 300 ≈ 142 KRW, CO₂ = 25 × 2.31 ≈ 57.8 kg.

Frequently Asked Questions

What is fuel efficiency?
Fuel efficiency is the distance you can drive on one liter of fuel (km/L). The manufacturer's official rating can differ from real-world figures depending on driving conditions (city/highway, driving habits, air conditioning use, and so on).
How do I check my fuel efficiency (km/L)?
You can find the official rating on your vehicle registration document or the manufacturer's website. Real-world efficiency is typically 70-90% of the official rating, depending on driving habits and road conditions.
How is a round trip calculated?
When you select round trip, the entered distance is doubled to compute the fuel needed and total fuel cost. The cost per km, however, is calculated identically based on the full round-trip distance.
What are the CO₂ emissions per liter?
Gasoline emits roughly 2.31 kg of CO₂ per liter. Diesel emits about 2.68 kg/L and LPG about 1.51 kg/L. This calculator estimates emissions on the gasoline basis (2.31 kg/L).
How much do fuel costs differ between gasoline and diesel?
Diesel is generally cheaper per liter than gasoline, and diesel vehicles tend to be more efficient, so the fuel cost difference can be significant. That said, fuel prices fluctuate constantly.
Are there any tips for saving on fuel?
Avoiding hard acceleration and braking, keeping tire pressure at the proper level, and reducing unnecessary cargo all improve efficiency. Driving at an economical speed (60-80 km/h) can also substantially cut fuel consumption.
How much do fuel costs differ compared with an electric vehicle?
Charging an EV typically costs about 1/3 to 1/5 of internal-combustion fuel costs. The exact figure depends on the charging method (slow/fast) and your electricity rate plan.
Updated 2026 pricing

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