Air  Density, Specific Weight and Thermal Expansion Coefficient vs. Temperature and Pressure
Online calculator, figures and tables showing density, specific weight and thermal expansion coefficients of air at temperatures ranging 100 to 1600 °C (140 to 2900 °F) at atmospheric and higher pressure  Imperial and SI Units.
Density is the ratio of the mass to the volume of a substance:
ρ = m/V [1]
where
ρ = density, units typically [kg/m^{3} ] or [lb/ft^{3} ]
m = mass, units typically [kg] or [lb]
V = volume, units typically [m^{3} ] or [ft^{3} ]
Specific weight is the ratio of the weight to the volume of a substance:
γ = (m * g)/V = ρ * g [2]
where
γ = specific weight, units typically [N/m^{3} ] or [lb_{f} /ft^{3} ]
m = mass, units typically [g] or [lb]
g = acceleration due to gravity, units typically [m/s^{2}] and value on Earth usually given as 9.80665 m/s^{2}or 32.17405 ft/s^{2}
V = volume, units typically [cm^{3} ] or [ft^{3} ]
ρ = density, units typically [g/cm^{3} ] or [lb/ft^{3} ]
Tabulated values and density units conversion are given below the figures . At the bottom of the page there are some examples of calculations using hot and cold air.
See also Air Composition and molecular weight , Density at varying pressure , Diffusion Coefficients for Gases in Air , Dynamic (absolute) and kinematic viscosity , Prandtl Number , Specific heat at varying temperature and Specific heat at varying pressure , Thermal Conductivity , Thermal Diffusivity , Properties at gasliquid equilibrium conditions and Air thermophysical properties , for other properties of air .
For other substances, see Density and specific weight o acetone , ammonia , argon , benzene , butane , carbon dioxide , carbon monoxide , ethane , ethanol , ethylene , helium , hydrogen , methane , methanol , nitrogen , oxygen , pentane , propane , toluene and water , as well as Density of crude oil , Density of fuel oils , Density of lubricating oil and Density of jet fuel as function of temperature.
Online Air Density Calculator
The calculator below can be used to calculate the air density and specific weight at given temperatures and atmospheric pressure.
The output density is given as kg/m^{3}, lb/ft^{3}, lb/gal(US liq) and sl/ft^{3} . Specific weight is given as N/m^{3} and lb_{f} / ft^{3}.
Note! Temperature must be within the ranges 100  1600 °C, 140  2900 °F, 175  1900 K and 315  3400 °R to get valid values.
Air density and specific weight at atmospheric pressure:
Air density at ambient temperature and pressure:
Air density at varying pressure and temperature:
Air density at gasliquid equilibrium pressure:
Air thermal expansion coefficient at atmospheric pressure:
Density, specific weight and thermal expansion coefficient of air at 1 atmosphere pressure, at temperatures given as °F:
For full table specific weight and thermal expansion coefficient  rotate the screen!
Temperature  Density  Specific weight  Thermal expansion coefficient  

[°F]  [lb_{m} /ft^{3}]  [sl/ft^{3} *10^{3}]  [lb_{m} /gal(US liq)]  [kg/m^{3}]  [lb_{f} /ft^{3}]  [N/m^{3}]  [x10^{3} °F^{1}] 
100  0.1104  3.431  0.01476  1.768  0.1104  17.34  2.83 
50  0.0968  3.010  0.01295  1.551  0.0968  15.21  2.48 
20  0.0902  2.803  0.01206  1.445  0.0902  14.17  2.30 
0  0.0862  2.681  0.01153  1.382  0.0862  13.55  2.20 
10  0.0844  2.624  0.01128  1.352  0.0844  13.26  2.15 
20  0.0826  2.569  0.01105  1.324  0.0826  12.98  2.10 
30  0.0810  2.516  0.01082  1.297  0.0810  12.72  2.06 
40  0.0793  2.466  0.01061  1.271  0.0793  12.46  2.02 
50  0.0778  2.418  0.01040  1.246  0.0778  12.22  1.98 
60  0.0763  2.372  0.01020  1.222  0.0763  11.99  1.94 
70  0.0749  2.327  0.01001  1.199  0.0749  11.76  1.90 
80  0.0735  2.284  0.00982  1.177  0.0735  11.55  1.87 
100  0.0709  2.203  0.00948  1.135  0.0709  11.14  1.80 
120  0.0685  2.128  0.00915  1.097  0.0685  10.75  1.74 
140  0.0662  2.057  0.00885  1.060  0.0662  10.40  1.68 
160  0.0641  1.991  0.00856  1.026  0.0641  10.06  1.63 
180  0.0621  1.929  0.00830  0.994  0.0621  9.75  1.58 
200  0.0602  1.870  0.00804  0.964  0.060  9.45  1.53 
250  0.0559  1.738  0.00747  0.896  0.0559  8.78  1.41 
300  0.0522  1.622  0.00698  0.836  0.0522  8.20  1.30 
350  0.0489  1.521  0.00654  0.784  0.0489  7.69  1.23 
400  0.0461  1.432  0.00616  0.738  0.0461  7.24  1.16 
450  0.0436  1.354  0.00582  0.698  0.0436  6.84  1.10 
500  0.0410  1.274  0.00548  0.656  0.0410  6.43  1.05 
600  0.0371  1.152  0.00496  0.599  0.0371  5.82  0.96 
700  0.0340  1.057  0.00455  0.545  0.0340  5.35  0.88 
800  0.0315  0.978  0.00421  0.5042  0.0315  4.94  0.81 
1000  0.0272  0.845  0.00363  0.4354  0.0272  4.27  0.70 
1200  0.0239  0.743  0.00319  0.3827  0.0239  3.75  0.61 
1400  0.0213  0.663  0.00285  0.3416  0.0213  3.35  0.54 
1600  0.0193  0.599  0.00257  0.3085  0.0193  3.03  0.49 
1800  0.0176  0.546  0.00235  0.2813  0.0176  2.76  0.45 
2000  0.0161  0.501  0.00216  0.2583  0.0161  2.53  0.42 
Density and specific weight of air at 1 atmosphere pressure, at temperatures given as °C:
For full table specific weight and thermal expansion coefficient  rotate the screen!
Temperature  Density  Specific weight  Thermal expansion coefficient  

[°C]  [kg/m^{3}]  [lb_{m} /ft^{3}]  [sl/ft^{3} *10^{3}]  [lb_{m} /gal(US liq)]  [N/m^{3} ]  [lb_{f} /ft^{3}]  [x10^{3} K^{1}] 
75  1.783  0.1113  3.460  0.01488  17.49  0.11131  5.14 
50  1.582  0.0988  3.070  0.01320  15.52  0.09878  4.55 
25  1.422  0.0888  2.759  0.01187  13.94  0.08877  4.08 
15  1.367  0.0853  2.652  0.01141  13.40  0.08532  3.92 
10  1.341  0.0837  2.601  0.01119  13.15  0.08370  3.84 
5  1.316  0.0821  2.553  0.01098  12.90  0.08214  3.76 
0  1.292  0.0806  2.506  0.01078  12.67  0.08063  3.69 
5  1.268  0.0792  2.461  0.01059  12.44  0.07919  3.62 
10  1.246  0.0778  2.418  0.01040  12.22  0.07780  3.56 
15  1.225  0.0765  2.376  0.01022  12.01  0.07645  3.50 
20  1.204  0.0752  2.336  0.01005  11.81  0.07516  3.43 
25  1.184  0.0739  2.297  0.00988  11.61  0.07390  3.38 
30  1.164  0.0727  2.259  0.00972  11.42  0.07269  3.32 
40  1.127  0.0704  2.188  0.00941  11.06  0.07039  3.21 
50  1.093  0.0682  2.120  0.00912  10.72  0.06822  3.12 
60  1.060  0.0662  2.057  0.00885  10.40  0.06619  3.02 
80  1.000  0.0625  1.941  0.00835  9.81  0.06245  2.85 
100  0.9467  0.0591  1.837  0.00790  9.28  0.05910  2.70 
125  0.8868  0.0554  1.721  0.00740  8.70  0.05536  2.51 
150  0.8338  0.0521  1.618  0.00696  8.18  0.05206  2.33 
175  0.7868  0.0491  1.527  0.00657  7.72  0.04912  2.22 
200  0.7451  0.0465  1.446  0.00622  7.31  0.04651  2.10 
225  0.7078  0.0442  1.373  0.00591  6.94  0.04419  2.01 
300  0.6168  0.0385  1.197  0.00515  6.05  0.03850  1.76 
400  0.5238  0.0327  1.016  0.00437  5.14  0.03270  1.52 
500  0.4567  0.0285  0.886  0.00381  4.48  0.02851  1.32 
600  0.4043  0.0252  0.784  0.00337  3.96  0.02524  1.16 
700  0.3626  0.0226  0.704  0.00303  3.56  0.02264  1.03 
800  0.3289  0.0205  0.638  0.00274  3.23  0.02053  0.94 
900  0.3009  0.0188  0.584  0.00251  2.95  0.01879  0.86 
1000  0.2773  0.0173  0.538  0.00231  2.72  0.01731  0.80 
1100  0.2571  0.0160  0.499  0.00215  2.52  0.01605  0.75 
kilogram/cubic meter [kg/m^{3} ] = gram/liter [g/l], kilogram/liter [kg/l] = gram/cubic centimeter [g/cm^{3} ]= ton(metric)/cubic meter [t/m^{3} ], once/gallon(US liquid) [oz/gal(US liq)] pound/cubic inch [lb/in^{3} ], pound/cubic foot [lb/ft^{3} ], pound/gallon(UK) [lb/gal(UK)], pound/gallon(US liquid) [lb/gal(US liq)], slug/cubic foot [sl/ft^{3} ], ton(short)/cubic yard [ton(short)/yd^{3} ], ton(long)/cubic yard [yd^{3} ]
 1 g/cm^{3} = 1 kg/l = 1000 kg/m^{3} = 62.428 lb/ft^{3} = 0.03613 lb/in^{3} = 1.9403 sl/ft^{3} = 10.0224 lb/gal(UK) = 8.3454 lb/gal(US liq) = 0.5780 oz/in^{3} = 0.7525 ton(long)/yr^{3}
 1 g/l = 1 kg/m^{3} = 0.001 kg/l = 0.000001 kg/cm^{3} = 0.001 g/cm^{3} = 0.99885 oz/ft^{3} = 0.0005780 oz/in^{3} = 0.16036 oz/gal(UK) = 0.1335 oz/gal(US liq) = 0.06243 lb/ft^{3} = 3.6127x105 lb/in^{3} = 1.6856 lb/yd^{3} = 0.010022 lb/gal(UK) = 0.0083454 lb/gal(US liq) = 0.0007525 ton(long)/yd^{3} = 0.0008428 ton(short)/yd^{3}
 1 kg/l = 1 g/cm^{3} = 1000 kg/m^{3} = 62.428 lb/ft^{3} = 0.03613 lb/in^{3} = 1.9403 sl/ft^{3} = 8.3454 lb/gal(US liq) = 0.5780 oz/in^{3} = 0.7525 ton(long)/yr^{3}

1 kg/m^{3} = 1 g/l = 0.001 kg/l = 0.000001 kg/cm^{3} = 0.001 g/cm^{3} = 0.99885 oz/ft^{3} = 0.0005780 oz/in^{3} = 0.16036 oz/gal(UK) = 0.1335 oz/gal(US liq) = 0.06243 lb/ft^{3} = 3.6127x105 lb/in^{3} = 1.6856 lb/yd^{3} = 0.010022 lb/gal(UK) = 0.008345 lb/gal(US liq) = 0.0007525 ton(long)/yd^{3} = 0.0008428 ton(short)/yd^{3}
 1 lb/ft^{3} = 27 lb/yd^{3} = 0.009259 oz/in^{3} = 0.0005787 lb/in^{3} = 16.01845 kg/m^{3} = 0.01602 g/cm^{3} = 0.1605 lb/gal(UK) = 0.1349 lb/gal(US liq) = 2.5687 oz/gal(UK) = 2.1389 oz/gal(US liq) = 0.01205 ton(long)/yd^{3} = 0.0135 ton(short)/yd^{3}
 1 lb/gal(UK) = 0.8327 lb/gal(US liq) = 16 oz/gal(UK) = 13.323 oz/gal(US liq) = 168.179 lb/yd^{3} = 6.2288 lb/ft^{3} = 0.003605 lb/in3 = 0.05767 oz/in^{3} = 99.7764 kg/m^{3} = 0.09977 g/cm^{3} = 0.07508 ton(long)/yd^{3} = 0.08409 ton(short)/yd^{3}
 1 lb/gal(US liq) = 1.2009 lb/gal(UK) = 19.215 oz/gal(UK) = 16 oz/gal(US liq) = 201.97 lb/yd^{3} = 7.4805 lb/ft^{3} = 0.004329 lb/in3 = 0.06926 oz/in^{3} = 119.826 kg/m^{3} = 0.1198 g/cm^{3} = 0.09017 ton(long)/yd^{3} = 0.1010 ton(short)/yd^{3}
 1 lb/in^{3} = 1728 lb/ft^{3} = 46656 lb/yd^{3} = 16 oz/in^{3} = 27680 kg/m^{3} = 27.680 g/cm^{3} = 277.419 lb/gal(UK) = 231 lb/gal(US liq) =4438.7 oz/gal(UK) = 3696 oz/gal(US liq) = 20.8286 ton(long)/yd^{3} = 23.3280 ton(short)/yd^{3}
 1 oz/gal(UK) = 0.8327 oz/gal(US liq) = 6.2360 kg/m^{3} = 6.2288 oz/ft^{3} = 0.3893 lb/ft^{3} = 10.5112 lb/yd^{3}
 1 oz/gal(US liq) = 1.2009 oz/gal(UK) = 7.4892 kg/m^{3} = 7.4805 oz/ft^{3} = 0.4675 lb/ft^{3} = 12.6234 lb/yd^{3}
 1 sl/ft^{3} = 515.3788 kg/m^{3} = 514.7848 oz/ft^{3} = 0.2979 oz/in^{3} = 32.1741 lb/ft^{3} = 82.645 oz/gal(UK) = 68.817 oz/gal(US liq)
 1 ton(long)/yd^{3} = 1.12 ton(short)/yd^{3} = 1328.94 kg/m^{3} = 0.7682 oz/in^{3} = 82.963 lb/ft^{3} = 2240 lb/yd^{3} = 2.5786 sl/ft^{3} = 13.319 lb/gal(UK) = 11.0905 lb/gal(US liq)
 1 ton(short)/yd^{3} = 0.8929 ton(long)/yd^{3} = 1186.55 kg/m^{3} = 0.6859 oz/in^{3} = 74.074 lb/ft^{3} = 2000 lb/yd^{3} = 2.3023 sl/ft^{3} = 11.8921 lb/gal(UK) = 9.9023 lb/gal(US liq)
Example  Mass of Air at Temperature 100 ^{o}C
From the table above  the density of air is 0.946 kg/m^{3} at 100 ^{o}C. The mass of 10 m^{3} air can be calculated as
m = V ρ
= 10 [m^{3} ] * 0.946 [kg/m^{3} ] = 9.46 [kg]
where
m = mass [kg]
V = volume [m^{3} ]
ρ = density [kg/m^{3} ]
Example  Mass of Air at Temperature 20 ^{o}C
From the table above  the density of air is 1.205 kg/m^{3} at 20 ^{o}C. The mass of 10 m^{3} air can be calculated as
m = 10 [m^{3} ] * 1.205 [kg/m^{3} ] = 12.05 [kg]
Example  Lifting Force of a Hot Air Balloon
An air balloon with volume 10 m^{3} is heated to 100 ^{o}C. The temperature of the surrounding air is 20 ^{o}C. The change in gravity force (weight) of the air volume is the potential lifting force of the balloon. The lifting force can be calculated as
F _{ l } = dm a _{ g } = V dρ a _{ g }
= 10 [m^{3} ] *(1.205  0.946) [kg/m^{3} ]*9.81 [m/s^{2}] = 25.4 [N]
where
F _{ l } = lifting force  change in gravity force (weight) [N]
a _{ g } = acceleration of gravity (9.81 [m/s^{2}])
dm = V dρ = change of mass in the balloon [kg]
dρ = change in density due to temperature difference [kg/m^{3} ]
Density of crude oil as function of temperature 
Related Topics

Air Psychrometrics
Moist and humid air calculations. Psychrometric charts and Mollier diagrams. Aircondition systems temperatures, absolute and relative humidities and moisture content in air. 
Densities
Densities of solids, liquids and gases. Definitions and convertion calculators. 
Fluid Mechanics
The study of fluids  liquids and gases. Involving velocity, pressure, density and temperature as functions of space and time. 
Gases and Compressed Air
Properties of air, LNG, LPG and other common gases. Pipeline capacities and sizing of relief valves. 
Material Properties
Properties of gases, fluids and solids. Densities, specific heats, viscosities and more.
Related Documents

Acetone  Density and Specific Weight
Online calculator, figures and tables showing density and specific weight of acetone at temperatures ranging from 95 to 275 °C (138 to 530 °F) at atmospheric and higher pressure  Imperial and SI Units. 
Air  Composition and Molecular Weight
Dry air is a mechanical mixture of nitrogen, oxygen, argon and several other gases in minor amounts. 
Air  Density and Specific Volume vs. Altitude
Density and specific volume of air varies with elevation above sea level. 
Air  Density vs. Pressure and Temperature
Air density at pressure ranging 1 to 10 000 bara (14.5  145000 psi) and constant selected temperatures. 
Air  Diffusion Coefficients of Gases in Excess of Air
Diffusion coefficients (D_{12}) for gases in large excess of air at temperatures ranging 0  400 °C. 
Air  Dynamic and Kinematic Viscosity
Online calculator, figures and tables with dynamic (absolute) and kinematic viscosity for air at temperatures ranging 100 to 1600°C (150 to 2900°F) and at pressures ranging 1 to 10 000 bara (14.5  145000 psia)  SI and Imperial Units. 
Air  Humidifying by Adding Steam or Water
Air can be humidified by adding water or steam. 
Air  Humidity Ratio
The mass of water vapor present in moist air  to the mass of dry air. 
Air  Moisture Holding Capacity vs. Temperature
The moisture holding capacity of air increases with temperature. 
Air  Molecular Weight and Composition
Dry air is a mixture of gases where the average molecular weight (or molar mass) can be calculated by adding the weight of each component. 
Air  Prandtl Number
Prandtl number for air vs. temperature and pressure. 
Air  Properties at GasLiquid Equilibrium Conditions
Properties of air change along the boiling and condensation curves (temperature and pressure between triple point and critical point conditions). An air phase diagram included. 
Air  Specific Heat vs. Pressure at Constant Temperature
Figures and tables with isobaric (Cp) and isochoric (Cv) specific heat of air at constant temperature and pressure ranging 0.01 to 10000 bara. 
Air  Specific Heat vs. Temperature at Constant Pressure
Online calculator with figures and tables showing specific heat (Cp and Cv) of dry air vs. temperature and pressure. SI and imperial units. 
Air  Speed of Sound vs. Temperature
Speed of sound in air at standard atmospheric pressure with temperatures ranging 40 to 1000 °C (40 to 1500 °F)  Imperial and SI Units. 
Air  Thermal Conductivity vs. Temperature and Pressure
Online calculator with figures and tables showing air thermal conductivity vs. temperature and pressure. SI and imperial units. 
Air  Thermal Diffusivity vs. Temperature and Pressure
Figures and tables withdry air thermal diffusivity vs. temperarure and pressure. SI and Imperial units. 
Air  Thermophysical Properties
Thermal properties of air at different temperatures  density, viscosity, critical temperature and pressure, triple point, enthalpi and entropi, thermal conductivity and diffusivity and more. 
Air Conditioning  Cooling of Air and Condensate Generated
Water may condensate when air is cooled in air conditioning systems. 
Argon  Density and Specific Weight
Online calculator, figures and tables showing density and specific weight of argon, Ar, at varying temperature and pressure  Imperial and SI Units. 
Benzene  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and table showing density and specific weight of benzene, C_{6}H_{6}, at temperatures ranging from 5 to 325 °C (42 to 620 °F) at atmospheric and higher pressure  Imperial and SI Units. 
Butane  Density and Specific Weight vs. Temperature and Pressure
Online calculators, figures and tables showing density and specific weight of liquid and gaseous butane, C_{4}H_{10}, at varying temperarure and pressure, SI and Imperial units. 
Carbon dioxide  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of carbon dioxide, CO_{2}, at temperatures ranging from 50 to 775 °C (50 to 1400 °F) at atmospheric and higher pressure  Imperial and SI Units. 
Compressed Air  Pressure Drop Diagrams, Metric Units
Pressure loss in compressed air pipe lines. 
Dry Air  Thermodynamic and Physical Properties
Thermodynamic properties of dry air  specific heat, ratio of specific heats, dynamic viscosity, thermal conductivity, Prandtl number, density and kinematic viscosity at temperatures ranging 175  1900 K. 
Dry Air and Water Vapor  Density and Specific Volume vs. Temperature  Imperial Units
Density and specific volume of dry air and water vapor at temperatures ranging 225 to 900 degF (107 to 482 degC). 
Ethane  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of ethane, C_{2}H_{6}, at varying temperature and pressure  Imperial and SI Units. 
Ethanol  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of ethanol at temperatures ranging from 25 to 325 °C (10 to 620 °F) at atmospheric and higher pressure  Imperial and SI Units. 
Ethylene  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of ethylene, C_{2}H_{4}, at varying temperature and pressure  Imperial and SI Units. 
Helium  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of helium, He, at varying temperature and pressure  Imperial and SI Units. 
Hydrogen  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of hydrogen, H2, at temperatures ranging from 260 to 325 °C (435 to 620 °F) at atmospheric and higher pressure  Imperial and SI Units. 
Latent Heat Flow
Latent heat is the heat when supplied to or removed from air results in a change in moisture content  the temperature of the air is not changed. 
Methane  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of methane, CH_{4}, at temperatures ranging from 160 to 725 °C (260 to 1300 °F) at atmospheric and higher pressure  Imperial and SI Units. 
Methanol  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of methanol,CH_{3}OH, at varying temperature and pressure  Imperial and SI Units. 
Moist Air  Specific Volume
Specific volume of moist air is defined as the total volume of humid air per mass unit of dry air 
Moist Air  Weight of Water Vapor
Weight of water vapor in air 
Nitrogen  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of nitrogen, N_{2}, at temperatures ranging from 175 to 1325 °C (280 to 2400 °F) at atmospheric and higher pressure  Imperial and SI Units. 
Nitrogen  Thermophysical Properties
Chemical, Physical and Thermal Properties of Nitrogen  N_{2}. 
Oxygen  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of oxygen, O_{2}, at varying temperature and pressure  Imperial and SI Units. 
Pentane  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and table showing density and specific weight of pentane, C5H12, at temperatures ranging from 130 to 325 °C (200 to 620 °F) at atmospheric and higher pressure  Imperial and SI Units. 
Propane  Density and Specific Weight vs. Temperature and Pressure
Online calculator, figures and tables showing density and specific weight of propane, C3H8, at temperatures ranging from 187 to 725 °C (305 to 1300 °F) at atmospheric and higher pressure  Imperial and SI Units. 
Solubility of Air in Water
The amount of air that can be dissolved in water decreases with temperature and increases with pressure. 
Stack or Flue Effect
The stack or flue effect occurs when the outdoor temperature is lower than indoor temperature. 
Toluene  Density and Specific Weight vs. Teemperature and Pressure
Density and specific weight of liquid toluene. 
U.S. Standard Atmosphere vs. Altitude
Properties of the US standard atmosphere ranging 5000 to 250000 ft altitude. 
Wind Power
Power generation from wind.