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 of 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 
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