Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Methane - Thermophysical Properties

Chemical, Physical and Thermal Properties of Methane - CH4. Phase diagram included.

Sponsored Links

Methane, CH4, is a colorless odorless gas. It is also known as marsh gas or methyl hydride. The vapors are lighter than air.
Methane is easily ignited. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket.

Methane is used as feed stock to chemical industry and is the main constituent of the fuel natural gas.

Methane phase diagram

Chemical, physical and thermal properties of methane:
Values are given for gas phase at 25 °C /77 °F / 298 K and 1 atm., if not other phase, temperature or pressure given.

For full table with Imperial Units - rotate the screen!

Property Value Unit Value Unit Value Unit Value Unit
Autoignition temperature 810 K

537 °C

999 °F

Boiling Point 111.51 K -161.6 °C -259.0 °F
Critical density 10.139 mol/dm3 162.7 kg/m3 0.3156 slug/ft3 10.15 lb/ft3
Critical Pressure 4.5992 MPa=MN/m2 45.99 bar 45.39 atm 667.1 psi=lbf/in2
Critical Temperature 190.56 K -82.59 °C -116.66 °F
Critical Volume 98.63 cm3/mol 0.00615 m3/kg 3.169 ft3/slug 0.0985 ft3/lb
Density, gas 41.0 mol/m3 0.657 kg/m3 0.00127 slug/ft3 0.0410 lb/ft3
Density, gas at STP; 32°F/0°C 1 atm 44.7 mol/m3 0.7168 kg/m3 0.00139 slug/ft3 0.0447 lb/ft3
Density, liquid at -260 °F/-162°C 26429 mol/m3 422.6 kg/m3 0.820 slug/ft3 26.38 lb/ft3
Flammable, gas and liquid yes
Flash point 85 K -188 °C -306 °F
Gas constant - R 518.28 J/kg K 0.1440 Wh/(kg K) 3099 [ft lbf/slug °R] 96.329 [ft lbf/lb °R]
Gibbs free energy of formation -51 kJ/mol -3179 kJ/kg -1367 Btu/lb
Heat (latent) of vaporation 8.19 kJ/mol 511 kJ/kg 219.48 Btu/lb
Specific heat, Cp 35.8 J/mol K 2.232 kJ/kg K 0.533 Btu/lb°F or cal/g K
Specific Heat, Cv 27.4 J/mol K 1.709 kJ/kg K 0.408 Btu/lb°F or cal/g K
Heat of combustion -890.8 kJ/mol -55528 kJ/kg -23.9 Btu/lb
Heat(enthalpy) of formation -75.00 kJ/mol -4675 kJ/kg -2010 Btu/lb
log KOW (Octanol/Water Partition Coefficient) 1.09
Melting point 90.55 K -182.6 °C -296.7 °F
Molecular Weight 16.042 g/mol 0.03537 lb/mol
Solubility in water 0.022 mg/ml
Sound velocity 446 m/s
Specific Gravity (density relativ to air), 0°C/32°F 0.554
Specific Heat Ratio - Cp/Cv 1.31
Specific Volume 0.0244 m3/mol 1.52 m3/kg 784.44 ft3/slug 24.38 ft3/lb
Standard molar entropy, S° 186 J/mol K 11.59 kJ/kg K 2.77 Btu/lb °F
Surface tension at -161 °C / -258 °F 14 dynes/cm 0.014 N/m
Thermal Conductivity 0.0339 W/m°C 0.019587 Btu/hr ft °F
Triple point pressure 0.011696 MPa=MN/m2 0.117 bar 0.115 atm 1.70 psi=lbf/in2
Triple point temperature 90.69 K -182.456 °C -296.42 °F
Vapor (saturation) pressure 62.12 MPa=MN/m2 466000 mm Hg 613.07 atm 9010 psi=lbf/in2
Vapor (saturation) pressure at 38 °C /100 °F 34.47 MPa=MN/m2 258574 mm Hg 340.18 atm 4999 psi=lbf/in2
Viscosity, dynamic (absolute) 0.01107 cP 7.44 [lbm /ft s*10-6] 0.23 [lbf s/ft2 *10-6]
Viscosity, kinematic 17.08 cSt 183.8 [ft2/s*10-6]

Back to top

Follow the links below to get values for the listed properties of methane at varying pressure and temperature:

See also more about atmospheric pressure, and STP - Standard Temperature and Pressure & NTP - Normal Temperature and Pressure,
as well as Thermophysical properties of: Acetone, Acetylene, Air, Ammonia, Argon, Benzene, Butane, Carbon dioxide, Carbon monoxide, Ethane, Ethanol, Ethylene, Helium, Hydrogen, Hydrogen sulfide, Methanol, Nitrogen, Oxygen, Pentane, Propane, Toluene, Water and Heavy water, D2O.

Methane is a gas at standard conditions. However, at low temperature and/or high pressures the gas becomes a liquid or a solid.

The methane phase diagram shows the phase behavior with changes in temperature and pressure. The curve between the critical point and the triple point shows the methane boiling point with changes in pressure.

Methane phase diagram C

At the critical point there is no change of state when pressure is increased or if heat is added.

The triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.

Sponsored Links

Related Topics

Related Documents

Sponsored Links

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro .Add the Engineering ToolBox extension to your SketchUp from the SketchUp Pro Sketchup Extension Warehouse!

About the Engineering ToolBox!


We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.

Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

Google use cookies for serving our ads and handling visitor statistics. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected.

AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information.


This page can be cited as

  • Engineering ToolBox, (2008). Methane - Thermophysical Properties. [online] Available at: [Accessed Day Mo. Year].

Modify access date.

. .


3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Scientific Online Calculator

Scientific Calculator

3 10

Sponsored Links