AGA8-92DC Z-Factor Calculator | Natural Gas Compressibility

Temperature (°C): Gas temperature

Pressure (barA): Operating pressure

Methane Methane (CH₄)

Ethane Ethane (C₂H₆)

Propane Propane (C₃H₈)

Isobutane Isobutane (i-C₄H₁₀)

n-Butane n-Butane (n-C₄H₁₀)

Isopentane Isopentane (i-C₅H₁₂)

n-Pentane n-Pentane (n-C₅H₁₂)

n-Hexane n-Hexane (n-C₆H₁₄)

n-Heptane n-Heptane (n-C₇H₁₆)

n-Octane n-Octane (n-C₈H₁₈)

n-Nonane n-Nonane (n-C₉H₂₀)

n-Decane n-Decane (n-C₁₀H₂₂)

Nitrogen Nitrogen (N₂)

Oxygen Oxygen (O₂)

Carbon Monoxide Carbon Monoxide (CO)

Carbon Dioxide Carbon Dioxide (CO₂)

Hydrogen Hydrogen (H₂)

Hydrogen Sulfide Hydrogen Sulfide (H₂S)

Sum Components: Sum of all component mole fractions

Molar density: Molar density (mol/m³)

Relative Density: Air-relative molecular weight (air ≈ 28.9647 g/mol)

Mass Density: Mass density (kg/m³)

Base Density: Standart condition density (kg · m⁻³) (@ 20 °C, 101.325 kPa)

Z-Factor: Calculated compressibility

AGA8 Details
AGA8 is the American Gas Association's standard equation of state used to calculate the compressibility (Z-factor) and density of natural gas from its composition, pressure, and temperature. It ensures accurate gas flow and volume measurements in pipelines and custody transfer. The standard is widely applied in the oil and gas industry and is aligned with ISO 12213 for international use.

ISO 12213 has three parts: Part 1 gives general guidelines, Part 2 defines the detailed (AGA8 Detail) method, and Part 3 covers the simplified (Gross) method for easier applications.

AGA8 Application Restrictions:
Pressure: 0 MPa to 12 MPa (0 to 120 bar)
Temperature: 263 K to 338 K (-10°C to 65°C)
Superior Calorific Value: 30 MJ/m³ to 45 MJ/m³
Relative Density: 0.55 to 0.80

AGA8 References:
ISO 12213-2:1997 Standard (PDF)
Repository for the AGA 8 from NIST
Repository with supplementary files to AGA 8
Official page for ISO 12213-2:1997 Standard (paid)
Repository for FORTRAN, PASCAL and C language
Community Python Implementation of AGA8 DETAILS
Python package for calculating gas properties using the AGA8

AGA8-92DC Compressibility Factor Calculator