If you are an oil & gas professional, there’s a high chance you’ve either thought about this question or been asked it at least once on site, in a meeting, or during training. How much natural gas do we actually get from 1 liter of LNG?

This simple question explains the LNG expansion ratio, one of the most critical concepts in LNG storage, transport, and safety engineering. It sounds simple, but the answer reveals one of the most powerful principles behind global LNG logistics—the 600-to-1 expansion ratio, a phenomenon that makes long-distance natural gas transport economically and technically possible.

The Short Answer (Industry Standard)

1 liter(litre) of LNG produces approximately 600 litres of natural gas when it is regasified and returned to normal temperature and pressure.

This relationship is commonly expressed as:

LNG Expansion Ratio = 1 : 600 times

1 Liter LNG to Natural Gas Conversion Explained

Why LNG Expands 600 Times

Natural gas—primarily methane—is extremely light and occupies a large volume in its gaseous state. Instead of compressing it to impractically high pressures, the LNG industry relies on cryogenic liquefaction.

What Happens During Liquefaction?

• Natural gas is cooled to –162°C

• At this temperature, it condenses into a liquid

• LNG becomes clear, colorless, non-toxic, and non-corrosive

• The volume reduces by about 600 times

When LNG is warmed during regasification, it returns to its gaseous form and expands back to its original volume.

Understanding “600 Liters” vs “600 Times”

Both expressions are correct—but they are used differently.

Volume-based expansions

The expansion ratio applies to any unit of volume:

• 1 liter of LNG → ~600 liters of natural gas

• 1 cubic meter of LNG → ~600 cubic meters of natural gas

• 1 gallon of LNG → ~600 gallons of natural gas

That’s why professionals often say “LNG expands 600 times” rather than fixing a specific unit.For readers who want a general background, Liquefied natural gas (LNG) is a form of natural gas that is cooled into liquid state for easier storage and transportation

The Engineer’s Perspective: Kilograms (Mass-Based View)

In engineering and operations, mass (kg) is preferred because it does not change with temperature or pressure.

What Happens to 1 kg of LNG?

• Mass remains constant:

  • 1 kg of LNG → 1 kg of natural gas

• Liquid volume:

  • 1 kg of LNG ≈ 2.2 liters

  • LNG density ≈ 450 kg/m³

• Gas volume at standard conditions:

  • 1 kg of natural gas ≈ 1.4 cubic meters

  • Equivalent to ~1,400 liters of gas

Why LNG? Why the 600:1 Ratio Is a Game-Changer

 Is Preferred Over CNG for Long Distances

LNG is about 2.4 times more energy-dense than CNG, which is why LNG dominates international shipping and large-scale storage.

1. Shipping Efficiency

A single LNG carrier can transport the energy equivalent of hundreds of millions of cubic metres of natural gas. Transporting that same energy in gaseous form would require an unrealistic number of vessels.

2. Storage Optimization

LNG allows utilities and countries to store large quantities of energy in a compact footprint, supporting peak demand management and energy security.

3. Global Energy Connectivity

Liquefaction connects gas-producing regions with demand centres across continents, making natural gas a globally traded commodity.

Safety and Operational Reality

LNG is not explosive in liquid form. However, its 600-fold expansion requires strict control.

If LNG is trapped in a closed system and allowed to warm:

• Pressure rises rapidly

• Structural failure can occur

This is why LNG facilities use:

• Cryogenic insulation

• Pressure relief systems

• Boil-off gas (BOG) handling systems

LNG calculations are based on a basic physics rule:

Mass = Density × Volume

LNG is very dense compared to natural gas. That is why a small amount of LNG can produce a very large amount of gas.

The average density of LNG is about 450 kg per cubic meter.

• 1 cubic meter = 1000 liters

• So, 1 liter = 0.001 cubic meter

Now apply the formula:

450 × 0.001 = 0.45 kg

This means 1 liter of LNG weighs about 0.45 kg.

When this LNG is warmed and converted back to gas:

• 1 kg of natural gas occupies about 1.4 cubic meters

• That equals 1400 liters of gas

So a small liquid volume becomes a very large gas volume.
This is why LNG expands roughly 600 times.

LNG Expansion Calculation (Quick Box)

• LNG density ≈ 450 kg/m³

• 1 liter LNG = 0.001 m³

• Mass = 450 × 0.001 = 0.45 kg

• 1 kg gas ≈ 1.4 m³ (1400 liters)

• Expansion ratio ≈ 600 : 1

Technical Accuracy Check

• Is it exactly 600?
  No. The expansion ratio typically ranges from 1:580 to 1:610, depending on gas composition (methane, ethane, and propane content).

• Reference conditions:
  Values assume standard temperature and pressure (around 15°C at sea level).

Quick Reference Table

Final Takeaway

The 600-to-1 expansion ratio is the foundation of the LNG industry.
It transforms natural gas from a bulky, difficult-to-transport vapour into a compact, manageable liquid—bridging global supply with local demand.

One litre of LNG may look small, but it carries enormous energy potential.

LNG calculations are based on a simple physics rule: Mass = Density × Volume, which is explained in detail along with other units used in LNG engineering