Standard temperature variation at different altitudes (up to 105 km)
Sea level temperature
Altitude (H)

Altitude temperature
Presurre:
Density:
 
Sound Speed:
 
Temperature Ratio:
 
T (Altitude) / T (Sea level)
Pressure Ratio:
P (Altitude) / P (Sea level)
Density Ratio:
D (Altitude) / D (Sea level)

Definition of standard atmosphere
Definition Values
Pressure altitude
The altitude determined by comparing the ambient pressure of air to the standard pressure of the standard atmosphere.
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Density altitude
The altitude determined by measuring the actual air density and comparing it to the standard atmosphere.
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Geometric altitude Z
Actual height measured from sea level.
E-earth radius
Geometric altitude
E = 6356.766 km
Geopotential altitude H
Altitude based on the variation in the earth gravity as a function of altitude.
Geopotential altitude
Sea level standard temperature T0 T0 = 288.15 K = 15 ̊C
Standard sea level pressure P0 P0 = 101 325 Pa
Sea level standard density ρ0 = 1.225 kg/m3
Sea level gravitational acceleration g g = 9.806 65 m/s2
Universal gas constant R R = 8.314 47 J/(mol∙K)
Molar mass of dry air M M = 0.028 964 4 kg/mol
Speed of sound c c = 340.3 m/s
Viscosity 1.789∙10-5 (kg∙s)/m
Kinematic viscosity 1.460∙10-5 m2/s
Thermal conductivity 0.025 96 (W∙K)/m
Specific heat Cp Cp = 1005 (J∙K)/kg
Specific heat Cv Cv = 717.98 (J∙K)/kg
Ratio of specific heats 1.4