Fuel Cost Calculator

Last updated: 2026-06-25

TL;DR

Fuel cost = distance ÷ fuel economy × fuel price. For example, driving 30 km at 12 km/L and 1,700 won/L is 30 ÷ 12 × 1,700 = 4,250 won.

Enter the one-way distance and this calculator shows the one-way and round-trip fuel cost plus a monthly (round-trip × 22 days) commuting cost.

Enter Trip Details

km
Enter the one-way distance. The round-trip is converted automatically.
km/L
Enter the combined or real-world fuel economy.
won/L
Enter the current price at the pump (won/L).

This is an estimate for reference. Real-world fuel economy varies with city/highway driving, air conditioning, and load, and fuel prices change frequently.

How to Use

  1. Enter the distance — enter the one-way distance (km).
  2. Enter fuel economy and price — enter the car's fuel economy (km/L) and the current fuel price (won/L).
  3. Check the result — press Calculate to see the one-way and round-trip fuel cost and the monthly (round-trip × 22 days) cost.

How Fuel Cost Is Calculated

Fuel cost is found by dividing the distance by fuel economy to get the fuel needed (L), then multiplying by the fuel price (won/L). The formula is fuel cost = distance ÷ fuel economy × fuel price. For the same distance, higher fuel economy and lower fuel prices mean lower cost.

Fuel cost by economy at 30 km one-way, 1,700 won/L
Fuel economyOne-way costRound-trip cost
8 km/L6,375 won12,750 won
12 km/L4,250 won8,500 won
16 km/L3,188 won6,375 won
20 km/L2,550 won5,100 won

The monthly fuel cost is the round-trip cost multiplied by the number of commuting days (this calculator uses 22 days for a 5-day week). If you don't know your fuel economy precisely, find your real-world economy first with the fuel economy calculator using distance and actual fuel added, then use that value.

Frequently Asked Questions (FAQ)

How is fuel cost calculated?

Fuel cost = distance ÷ fuel economy × fuel price. For example, driving 30 km in a 12 km/L car at 1,700 won/L costs 30 ÷ 12 × 1,700 = 4,250 won.

How do I get the round-trip fuel cost?

Round-trip fuel cost is the one-way cost multiplied by 2. This calculator shows both one-way and round-trip when you enter the one-way distance, and converts the round-trip into a monthly (22 weekday) commuting cost.

What if I don't know my fuel economy?

Use the combined fuel economy from your vehicle registration or the manufacturer's catalog. For more accuracy, find your real-world fuel economy with the fuel economy calculator using distance and actual fuel added, then enter that value. Real-world economy varies with city/highway driving and air conditioning use.

How many days is the monthly fuel cost based on?

The monthly fuel cost here is round-trip fuel cost × 22 days (a 5-day-per-week commute). If your commuting days differ, adjust the result proportionally.

Last updated: 2026-06-25