How Much Does Fuel Weigh? Petrol, Diesel, Jet Fuel & LPG Guide

Whether you are loading a commercial freight truck, calculating aircraft takeoff weight, or wondering how much extra weight a full tank adds to your car, knowing how much fuel weighs is critical.

Unlike water—where 1 liter equals roughly 1 kilogram—all common hydrocarbon fuels are lighter than water. Petrol, diesel, jet kerosene, and liquefied petroleum gas (LPG) float on water because their molecular density is significantly lower.

Petrol (Gasoline): 1 Liter = 0.74 kg (1.63 lbs) | 1 US Gallon = 6.18 lbs (2.80 kg) Diesel Fuel: 1 Liter = 0.835 kg (1.84 lbs) | 1 US Gallon = 7.05 lbs (3.20 kg) Jet A-1 Kerosene: 1 Liter = 0.804 kg (1.77 lbs) | 1 US Gallon = 6.71 lbs (3.04 kg) LPG (Propane Liquid): 1 Liter = 0.510 kg (1.12 lbs) | 1 US Gallon = 4.26 lbs (1.93 kg) 

Fuel Weight Comparison Table (Standard 15°C Conditions)

Because fuels expand and contract with changes in ambient temperature, international metrology standards (such as ASTM D1298 and ISO 3675) define standard fuel densities at 15°C (59°F).

1. Petrol (Gasoline): The Lightest Common Motor Fuel

Standard motor petrol is a volatile mixture of relatively short-chain hydrocarbons (C4 through C12).

• Weight per Liter: Between 0.71 kg and 0.77 kg (averaging ~0.74 kg at 15°C).
• Weight per US Gallon: Between 5.9 and 6.4 pounds (averaging ~6.18 lbs).

How Heavy is a Full Tank of Petrol?

When you pull up to a gas station and fill your car:

• Compact Hatchback (40 Liters / 10.5 Gal): Fuel weighs 29.6 kg (65.3 lbs).
• Mid-Size Sedan (55 Liters / 14.5 Gal): Fuel weighs 40.7 kg (89.7 lbs).
• Full-Size Pickup or SUV (95 Liters / 25 Gal): Fuel weighs 70.3 kg (155.0 lbs).

Because a full tank adds up to 155 lbs of dead mass, test and track vehicles run minimal fuel to optimize power-to-weight ratios. Read our complete guide on how much a litre of petrol weighs for detailed breakdown charts.

2. Automotive Diesel: Heavy & Energy Dense

Diesel fuel contains longer, heavier hydrocarbon molecules (C10 through C22) than gasoline, giving it both higher volumetric energy density and significantly greater mass.

• Weight per Liter: Under European EN 590 standards, diesel density ranges from 0.820 to 0.845 kg/L (standard average: 0.835 kg/L).
• Weight per US Gallon: 6.97 to 7.05 pounds.

Because diesel is ~13% heavier than petrol, a long-haul commercial tractor-trailer with dual 150-gallon tanks (300 US gallons / ~1,135 liters) carries approximately 2,100 lbs (952 kg) of fuel when topped off. This substantial mass directly impacts highway axle-weight scale compliance. Explore more in our dedicated article on how much a litre of diesel weighs.

3. Aviation Fuels: Jet A-1 vs. Avgas

In commercial aviation, volume measurements (liters and gallons) are virtually useless for flight dispatchers. Pilots and dispatchers plan flights strictly in kilograms or pounds of fuel burn.

graph TD
    A[Aviation Fuel Types] --> B[Jet A-1 / Kerosene: 0.804 kg/L]
    A --> C[Avgas 100LL / Aviation Gas: 0.715 kg/L]
    B --> D[Used in Turboprops & Commercial Jets]
    C --> E[Used in Piston-Engine Prop Aircraft]

• Jet A-1 / Jet A: Kerosene-based fuel used in turbine engines (Airbus, Boeing, business jets). Average density is 0.804 kg/L (6.71 lb/US gal). A Boeing 777 loading 100,000 liters of jet fuel takes on 80,400 kg (177,250 lbs) of payload weight.
• Avgas 100LL: High-octane leaded gasoline used in small piston aircraft (Cessna, Piper). Density is 0.715 kg/L (5.97 lb/US gal).

Flight crews measure fuel density with hydrometers prior to flight to confirm that the mass indicated by fuel tank probes matches true weight.

4. Liquefied Petroleum Gas (LPG) & Propane

LPG is stored under pressure as a liquid. Because propane (C3H8) and butane (C4H10) have small molecular chains:

• Pure liquid propane weighs only 0.51 kg per liter (4.26 lb/US gal).
• Standard commercial propane/butane mix weighs ~0.54 kg per liter.

How Much Does an LPG Cylinder Weigh?

Propane cylinders are labeled by the mass of the gas they hold, not their total weight:

• 20 lb Propane Grill Tank (US): Holds 20 lbs (9.1 kg / 17.8 L) of propane gas. The empty steel cylinder (tare) weighs ~17 lbs (7.7 kg). Total full weight is ~37 lbs (16.8 kg).
• 13 kg Gas Cylinder (UK / Europe): Holds 13 kg (24 L) of gas. The empty tare weighs ~12–14 kg. Total full weight is ~25–27 kg (55–60 lbs).

How Temperature Distorts Fuel Volume

Fuel volume expands significantly in warm weather. For every 10°C (18°F) rise in temperature, petrol volume expands by approximately 1.2%, while diesel expands by ~0.95%.

If you buy 1,000 liters of diesel at 35°C (95°F) in midday summer heat, you receive approximately 819 kg of fuel mass. That same 1,000 liters chilled to 5°C (41°F) in winter contains 843 kg of fuel mass—a free 24 kg (53 lbs) surplus of energy.

For further background on commercial calibration and ASTM standards, consult our industrial fuel density guide.

Frequently Asked Questions

Which is heavier: a gallon of water or a gallon of diesel?

A gallon of water is significantly heavier. One US gallon of water weighs 8.34 lbs (3.78 kg), whereas one US gallon of diesel weighs 7.05 lbs (3.20 kg). Water is ~18% heavier than diesel.

How much does 100 liters of petrol weigh?

At standard 15°C temperature, 100 liters of unleaded petrol weighs approximately 74.0 kilograms (163.1 pounds).

How do I convert fuel liters to kilograms?

Multiply fuel volume in liters by its specific density: Mass (kg) = Volume (L) × Density (kg/L) For quick conversions across all fuels, use our Diesel to Kg Calculator or Petrol to Kg Calculator.