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Fuel consumption & trip cost calculator

Convert petrol or diesel efficiency units, enter price per litre or gallon, and get cost per distance plus trip fuel and cost.

Defaults to your region. Switch to compare any other scale.

Result

11.6667

Trip fuel cost

12.618 L × 0.9246 / L

  • Canonical L/100 km7.8405 L/100 km
  • How calculatedL/100 km = 235.215 ÷ 30 = 7.8405
  • Cost per 100 km7.2493
  • Cost per 100 mi11.6667
  • Cost per km0.0725
  • Cost per mi0.1167
  • Fuel for trip12.618 L · 3.3333 US gal · 2.7756 Imp gal
  • Price per litre (normalized)0.9246

Via L/100 km (NIST gallons)

1 US gal = 3.785411784 L; 1 Imp gal = 4.54609 L; 1 mi = 1.609344 km. L/100 km = 235.215 ÷ 30 = 7.8405

All efficiency units

UnitSymbolValue
L/100 kmL/100 km7.8405
km/Lkm/L12.754
MPG (US gallon)MPG (US)30
MPG (UK / Imperial)MPG (UK)36.028
mi/Lmi/L7.9252

About this tool

Fuel economy is reported as energy-hungry (L/100 km) or distance-hungry (km/L, MPG). This page converts everything through L/100 km using exact factors: 1 US gallon = 3.785411784 L, 1 imperial gallon = 4.54609 L, 1 mile = 1.609344 km.

L/100 km = 235.214583 ÷ MPG (US) and L/100 km = 282.480936 ÷ MPG (UK). Price can be entered per litre, per US gallon or per UK gallon; costs are shown per 100 km, per 100 mi, per km and per mile.

Add a trip distance to see litres (and gallons) needed and total fuel cost. Pair with the EV efficiency calculator to compare electricity vs petrol for the same route. Educational estimates — real consumption varies with driving style and conditions.

Formula

  • Canonical: L/100 km
  • km/L = 100 ÷ (L/100 km)
  • L/100 km = 235.214583 ÷ MPG (US)
  • L/100 km = 282.480936 ÷ MPG (UK)
  • 1 US gal = 3.785411784 L · 1 Imp gal = 4.54609 L · 1 mi = 1.609344 km
  • Cost / 100 km = (L/100 km) × price_per_litre
  • Trip litres = distance_km × (L/100 km) ÷ 100

How it is calculated

  1. Enter efficiency and pick its unit (L/100 km, km/L, US/UK MPG, or mi/L).
  2. Enter fuel price and whether it is per litre, US gallon, or UK gallon.
  3. Optionally set trip distance (km or mi).
  4. Read cost per 100 km / 100 mi, trip litres and cost, plus the all-units efficiency table.
  5. Compare with the EV efficiency calculator for electricity vs petrol on the same route.

Questions

How do I convert MPG to L/100 km?

US: L/100 km = 235.214583 ÷ MPG. UK (imperial): L/100 km = 282.480936 ÷ MPG. The factors come from exact gallon and mile definitions.

EV vs petrol — cost per 100 km?

Petrol/diesel: cost/100 km = (L/100 km) × price per litre. EV: (kWh/100 km) × price per kWh on the EV efficiency calculator. Home overnight electricity is usually cheaper than pump fuel; fast DC public charging may not be.

US gallon or UK gallon?

A US gallon is exactly 3.785411784 L; an imperial (UK) gallon is exactly 4.54609 L. Always match the price unit to the MPG definition you use.

Are the results official advice?

No. Calculate This is an educational tool. For important decisions, check primary sources or ask a qualified professional.

Sources

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