Altimetry
  Functions on this Page:
  Temperature Conversion
Altitude Correction for Pressure Altitude
Pressure Altitude
Density Altitude
True Altitude

 
True Airspeed
Temperature Rise
Mach Number
Equivalent Airspeed
 

Temperature
Conversion

 
Temperature
     [oF]   [oC]     [oR]    [K]

     Enter a number in any box and get all the remaining box's results             

    

 

Altitude Correction for
Pressure Altitude

 
Altimeter Setting
    [InHg]    [HPa] or [mbar]  
Altitude Correction
   [ft]  [m]  

     Enter the altimeter setting or altitude correction  

 

Pressure
Altitude

 
Calibrated Altitude
    [ft]
  [m]
Altimeter Setting (QNH)
    [InHg]
  [HPa] or [mbar]
Pressure Altitude
    [ft]   [m]

    Enter any two fields (i.e. Altitude, Altimeter Setting or Pressure Altitude)
    then press "Eval" on any remaining field for that field's result

    QNH is a term not commonly used in the United States but used in many other countries. It is the altimeter setting setting
    such that the altimeter reads altitude above mean sea level at the airport level. In the U.S. this is referred to as the altimeter
    setting and is usually given by ATC (Air Traffic Control) or the airport ATIS (Airport Terminal Information Service)
    among other sources.

    Note that it does not matter the order that you enter the rows. The remaining row (field) will be
    calculated based on the values of the other two rows when the Eval button of that row is pressed.


   

 

QNH

 
Airport Altitude
    [ft]   [m]
Pressure Altitude at Airport
    [ft]   [m]
Altimeter Setting (QNH)
    [InHg]   [HPa] or [mbar]

    QNH is a term not commonly used in the United States but used in many other countries. It is the altimeter setting setting
    such that the altimeter reads altitude above mean sea level at the airport level. In the U.S. this is referred to as the altimeter
    setting and is usually given by ATC (Air Traffic Control) or the airport ATIS (Airport Terminal Information Service) among
    other sources. Pressure Altitude is the altitude the altimeter reads when set to the QNE setting 1013.25 hPa or
    approximately 29.92 InHg. QNE is also a term used more internationally but denotes the altimeter setting to obtain the
    pressure altitude reading.


    Note that it does not matter the order that you enter the rows. The remaining row (field) will be
    calculated based on the values of the other two rows when the Eval button of that row is pressed.
 

QFE

 
Pressure Altitude at Airport
    [ft]   [m]  
QFE Setting
    [InHg]   [HPa] or [mbar]  

    QFE is a term also not commonly used in the United States but referred to in many other countries. In practice it is not used
    very much but it is useful to know of it's existence. It is the altimeter setting such that the altimeter reads zero height at the
    airport level. Pressure altitude is the altitude the altimeter reads when set to the QNE setting 1013.25 hPa or approximately
    29.92 InHg. QNE is also a term used more internationally but denotes the altimeter setting to obtain the pressure altitude
    reading.

 

Density
Altitude

 
Pressure Altitude
  [ft]
[m]
Temperature
  [oF]
[oC] 
Density Altitude
    [ft] [m]

    Enter any two fields (i.e. Pressure Altitude, Temperature or Density Altitude) then press "Eval" on any remaining field
    for that field's result

    Note that it does not matter the order that you enter the rows. The remaining row (field) will be
    calculated based on the values of the other two rows when the Eval button of that row is pressed.

 

True
Altitude

 
Pressure Altitude (PA)
    [ft]   [m]
True Air Temperature (T)
    [oF]   [oC]
Calibrated Altitude (CA)
    [ft]   [m]
Station Altitude
    [ft]   [m]
True Altitude (TA)
    [ft]   [m]
          or    
Pressure Altitude (PA)
    [ft]   [m]
True Air Temperature (T)
    [oF]   [oC]
Altimeter Setting (QNH)
    [InHg]   [HPa] or [mbar]
Station Altitude
    [ft]   [m]
True Altitude (TA)
    [ft]   [m]
          or    
Calibrated Altitude (CA)
    [ft]   [m]
True Air Temperature (T)
    [oF]   [oC]
Altimeter Setting (QNH)
    [InHg]   [HPa] or [mbar]
Station Altitude
    [ft]   [m]
True Altitude (TA)
    [ft]   [m]

    Enter any four fields then press "Eval" on any remaining field for that field's result. True Altitude computations are
    inherently imprecise, please be cautious, particularly when extrapolating beyond typical conditions.

    Note 1: If you don't have the Station Altitude set it to zero

    Note 2: It does not matter the order that you enter the rows. The remaining row (field) will be
    calculated based on the values of the other rows when the Eval button of that row is pressed.

    Note 3: True Air Temperature (T) is also referred to as Outside Air Temperature (OAT) or Static Air Temperature (SAT).
     True Air Temperature (T) is sometimes abbreviated (TAT). It is NOT to be confused to Total Air Temperature also
     abbreviated (TAT) which is the same as Indicated Temperature (IAT) or Ram Air Temperatures (RAT).

 

True
A
irspeed

 
  Main Variables
Pressure Altitude (PA)     [ft]   [m]
Recovery Coefficient (CT)    
Indicated Air Temperature (IAT)     [oF]   [oC]
Calibrated Airspeed (CAS)     [knots]   [Km/h]
True Airspeed (TAS)     [knots]   [Km/h]
 
  Correlated Variables
True Air Temperature (T)       [oF]   [oC]
Mach (M)      
Pitot Tube Impact Pressure (qc)       [InHg]   [HPa] or [mbar]
Static Pressure (P)       [InHg]   [HPa] or [mbar]
Pitot Tube Total Pressure (P't=qc+P)       [InHg]   [HPa] or [mbar]
Speed of Sound (CS)       [knots]   [Km/h]
Temperature Rise (ΔT=IAT-T)       [ΔoF]   [ΔoC]

                            or

  Main Variables
Pressure Altitude (PA)     [ft]   [m]
Calibrated Airspeed (CAS)     [knots]   [Km/h]
True Air Temperature (T)     [oF]   [oC]
True Airspeed (TAS)     [knots]   [Km/h]
 
  Correlated Variables
Mach (M)      
Pitot Tube Impact Pressure (qc)       [InHg]   [HPa] or [mbar]
Static Pressure (P)       [InHg]   [HPa] or [mbar]
Pitot Tube Total Pressure (P't=qc+P)       [InHg]   [HPa] or [mbar]
Speed of Sound (CS)       [knots]   [Km/h]

    Enter any four fields in white on the upper portion or three fields in white on the lower portion then press "Eval" on
    that portion for any remaining field for that field's result. True Airspeed computations are somewhat imprecise, please be
    cautious, particularly when extrapolating beyond typical conditions. When calculating the Recovery Coefficient there is a
    vary narrow range of solutions. The model used takes into consideration compressibility and may be used for speeds
    beyond Mach 1. Correlated Variables display other information and are calculated from results once Eval has been pressed.

    Note 1: If you don't know the recovery coefficient set it to 1.0.


    Note 2: If you don't have the Calibrated Airspeed (CAS) use Indicated Airespeed (IAS) in place of CAS.

    Note 3: True Air Temperature (T) is also referred to as Outside Air Temperature (OAT) or Static Air Temperature (SAT).
     True Air Temperature (T) is sometimes abbreviated TAT. It is NOT to be confused to Total Air Temperature also
     abbreviated TAT which is the same as Indicated Temperature (IAT) or Ram Air Temperatures (RAT).


    Note 4: Indicated Temperature (IAT) is also referd to as Total Air Temperature (TAT) or Ram Air Temperature (RAT).
     Total Air Temperature (TAT) is NOT to be confused to True Air Temperature also abbreviated TAT (see note 2 above)


    Note 5: It does not matter the order that you enter the rows. The remaining row (field) will be
    calculated based on the values of the other rows when the Eval button of that row is pressed.

 

Temperature
Rise

 
True Airspeed (TAS)     [knots]   [Km/h]
Recovery Coefficient (CT)    
Temperature Rise (ΔT=IAT-T)      [ΔoF]   [ΔoC]

    Enter any two fields then press "Eval" on any remaining field for that field's result. When calculating the Recovery Coefficient
    there is a vary narrow range of solutions. The model used takes into consideration compressibility and may be used for speeds
    beyond Mach 1. To calculate True Air Temperature (T) use T=
IAT-ΔT. Where IAT is the Indicated Air Temperature and ΔT is
    the Temperature Rise.


   Note 1: If you don't know the Recovery Coefficient (CT) set it to 1.0.


   Note 2: True Air Temperature (T) is also referred to as Outside Air Temperature (OAT) or Static Air Temperature (SAT).
     True Air Temperature (T) is sometimes abbreviated TAT. It is NOT to be confused to Total Air Temperature also
     abbreviated TAT which is the same as Indicated Temperature (IAT) or Ram Air Temperatures (RAT).


    Note 3: Indicated Air Temperature (IAT) is also referd to as Total Air Temperature (TAT) or Ram Air Temperature (RAT).
     Total Air Temperature (TAT) is NOT to be confused to True Air Temperature also abbreviated TAT (see note 2 above)


    Note 4: It does not matter the order that you enter the rows. The remaining row (field) will be
    calculated based on the values of the other rows when the Eval button of that row is pressed.

 

Mach
Number

 
  Main Variables
Pressure Altitude (PA)     [ft]   [m]
Calibrated Airspeed (CAS)     [knots]   [Km/h]
Mach Number (M)     
 
  Correlated Variables
Pitot Tube Impact Pressure (qc)       [InHg]   [HPa] or [mbar]
Static Pressure (P)       [InHg]   [HPa] or [mbar]
Pitot Tube Total Pressure (P't=qc+P)       [InHg]   [HPa] or [mbar]

                            or

  Main Variables
True Airspeed (TAS)     [knots]   [Km/h]
Recovery Coefficient (CT)    
Indicated Air Temperature (IAT)     [oF]   [oC]
Mach Number (M)    
 
  Correlated Variables
True Air Temperature (T)       [oF]   [oC]
Speed of Sound (CS)       [knots]   [Km/h]
Temperature Rise (ΔT=IAT-T)       [ΔoF]   [ΔoC]

                            or

  Main Variables
True Airspeed (TAS)     [knots]   [Km/h]
True Air Temperature (T)     [oF]   [oC]
Mach Number (M)    
 
  Correlated Variables
Speed of Sound (CS)       [knots]   [Km/h]

    Enter any two fields in white on the upper portion, three in the middle, or two fields on the lower portion then press "Eval"
    on that portion for any remaining field for that field's result.

    Note 1: If you don't know the recovery coefficient set it to 1.0.


    Note 2: Indicated Air Temperature (IAT) is also referd to as Total Air Temperature (TAT) or Ram Air Temperature (RAT).
     Total Air Temperature (TAT) is NOT to be confused to True Air Temperature also abbreviated TAT. True Air
     Temperature (TAT) or (T) is also referred to as Outside Air Temperature (OAT) or Static Air Temperature (SAT)


    Note 3: It does not matter the order that you enter the rows. The remaining row (field) will be
    calculated based on the values of the other rows when the Eval button of that row is pressed.

 

Equivalent
Airspeed

 
  Main Variables
Pressure Altitude (PA)     [ft]   [m]
True Air Temperature (T)     [oF]   [oC]
True Airspeed (TAS)      [knots]   [Km/h]
Equivalent Airspeed (EAS)     [knots]   [Km/h]
 
  Correlated Variables
Calibrated Airspeed (CAS)       [knots]   [Km/h]
Mach (M)      
Pitot Tube Impact Pressure (qc)       [InHg]   [HPa] or [mbar]
Static Pressure (P)       [InHg]   [HPa] or [mbar]
Pitot Tube Total Pressure (P't=qc+P)       [InHg]   [HPa] or [mbar]
Speed of Sound (CS)       [knots]   [Km/h]

     Enter any three fields in white then press "Eval" on any remaining field for that field's result 

    Note 1: True Air Temperature (T) is also referred to as Outside Air Temperature (OAT) or Static Air Temperature (SAT).
     True Air Temperature (T) is sometimes abbreviated TAT. It is NOT to be confused to Total Air Temperature also
     abbreviated TAT which is the same as Indicated Temperature (IAT) or Ram Air Temperatures (RAT).


    Note 2: It does not matter the order that you enter the rows. The remaining row (field) will be
    calculated based on the values of the other rows when the Eval button of that row is pressed.