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Fuel Cost Calculator

Calculate fuel cost for any trip using km or miles, MPG, L/100km, or km/L with support for multiple currencies.

Updated

What is the Fuel Cost Calculator?

Estimate exactly how much any journey will cost, regardless of units. This calculator handles kilometers or miles, fuel by liter or gallon, and efficiency in MPG, L/100km, or km/L.

Three calculators in one: Trip Cost, How Far on a Budget, and Vehicle Comparison. Enter distance, efficiency, and price to get total cost, fuel needed, cost per km/mile, per-person split, and CO₂ emissions.

Features:

  • All major units: km/mi, MPG US/UK, km/L, L/100km
  • Multiple currencies supported
  • Round-trip toggle and passenger split
  • Petrol, diesel, LPG, and electric modes
  • Works entirely in your browser—no sign-up required

Use it for daily commutes, long-distance trips, delivery route planning, or comparing vehicle costs.

How it works

The calculator converts everything to a common base (kilometers and liters), then applies simple physics.

1. Choose your mode

  • Trip Cost: cost for a known distance
  • How Far: distance possible on a fixed budget
  • Compare Vehicles: side-by-side cost for two efficiencies

2. Enter your numbers

  • Distance and unit (km or miles)
  • Fuel efficiency and unit (km/L, L/100km, MPG US, MPG UK)
  • Fuel price and unit (per liter, per US gallon, per UK gallon)
  • Optional: round trip, passengers, fuel type

##s# 3. The math

All conversions use precise constants:

  • 1 mile = 1.609344 km
  • 1 US gallon = 3.785411784 L
  • 1 UK gallon = 4.54609 L

Step 1 – Efficiency to L/100km

  • MPG US: 235.214583 / mpg
  • MPG UK: 282.480936 / mpg
  • km/L: 100 / km_per_l
  • L/100km: stays as-is

Step 2 – Fuel needed fuel_liters = (distance_km × L_per_100km) / 100

Step 3 – Price per liter price_per_liter = price / gallons_to_liters (if needed)

Step 4 – Total cost total_cost = fuel_liters × price_per_liter

Step 5 – Extras

  • Cost per km = total_cost / distance_km
  • Cost per mile = total_cost / distance_miles
  • Per person = total_cost / passengers
  • CO₂ (kg) = fuel_liters × factor (petrol 2.31, diesel 2.68, LPG 1.51, electric 0)

For How Far, it reverses the formula: distance_km = (budget / price_per_liter) × 100 / L_per_100km

Examples

Karachi to Hyderabad round trip

180 km each way in a car doing 14 km per liter with petrol at 273.5 PKR per liter

Distance: 180 km, Round trip: yes, Efficiency: 14 km/L, Price: 273.5 PKR/L, Passengers: 1
 
Total cost: PKR 7,032.86, Fuel needed: 25.71 L, Cost per km: PKR 19.54, CO2: 59.4 kg

US road trip with MPG

300 miles at 28 MPG US with gas at 3.49 USD per US gallon

Distance: 300 mi, Efficiency: 28 MPG US, Price: 3.49 USD per gallon
 
Total cost: $37.39, Fuel needed: 10.71 US gal, Cost per mile: $0.12

Budget to distance

How far you can drive on PKR 3000 with 15 km per liter and fuel at 273.5 PKR per liter

Budget: PKR 3000, Efficiency: 15 km/L, Price: 273.5 PKR/L
 
Max distance: 164.5 km (102.2 mi), Fuel purchasable: 10.97 L

Compare two vehicles

Same 200 km trip comparing 12 km/L vs 18 km/L at 273.5 PKR per liter

Distance: 200 km, Vehicle A: 12 km/L, Vehicle B: 18 km/L, Price: 273.5 PKR/L
 
Vehicle A: PKR 4,558.33, Vehicle B: PKR 3,038.89, Saving: PKR 1,519.44 (33.3%)

Frequently asked questions

How do I calculate fuel cost for a trip?

Enter distance, your car's efficiency, and current fuel price. The calculator converts units, finds fuel needed, then multiplies by price. Example: 360 km round trip at 14 km/L uses 25.7 L. At 273.5 PKR/L, cost is about PKR 7,033.

What is the exact formula?

Total Cost = (Distance in km × Fuel consumption in L/100km ÷ 100) × Price per liter. If you use MPG, we first convert it to L/100km. For US MPG: L/100km = 235.214583 ÷ MPG.

Can I use MPG, L/100km, and km/L?

Yes. The tool accepts all four: MPG US, MPG UK, km per liter, and L/100km. It also accepts price per liter, per US gallon, or per UK gallon, and distance in km or miles.

What is the difference between US MPG and UK MPG?

A US gallon is smaller (3.785 L) than a UK gallon (4.546 L). So 30 MPG US equals about 36 MPG UK. The calculator handles both separately to avoid 20% errors.

How do I calculate cost for a round trip?

Turn on the "Round trip" toggle. It doubles the distance automatically before calculating fuel and cost.

Can I split fuel cost between passengers?

Yes. Set Passengers to 2, 3, 4, etc. The calculator shows total cost and cost per person instantly.

How do I find how far I can drive on a budget?

Switch to "How Far" mode. Enter your budget, efficiency, and fuel price. It returns maximum distance in km and miles, plus liters you can buy.

Does it work for diesel, petrol, and LPG?

Yes. Choose fuel type to get a more accurate CO₂ estimate. Petrol uses 2.31 kg CO₂/L, diesel 2.68 kg/L, LPG 1.51 kg/L. Electric sets CO₂ to 0 for tank-to-wheel.

Is the calculator accurate for Pakistan prices?

Yes. Defaults are set for Pakistan: kilometers, km/L, price per liter, PKR currency. Enter current pump price (e.g., 273.5 PKR/L) for live accuracy.

Can I compare two cars?

Use "Compare Vehicles" mode. Enter the same distance and price, but different efficiencies (e.g., 12 km/L vs 18 km/L). You'll see total cost for each, money saved, percentage saved, and CO₂ difference.

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