Standard Atmosphere Calculator

This standard atmosphere calculator is based on the 1976 model of the U.S. Standard Atmosphere 1976_Std_Atm_NASA-TM-X-74335.

Two input options are modeled, you can either provide:

  • altitude and ambient temperature
  • altitude and temperature offset (from Std. Atm.)

US Std. Atm. + Temp. Offset



Density Altitude:


Air Density:

Relative Density:

(SL ISA=1)

Sonic Speed:


Disclaimer (the simple version):

Every effort has been made to ensure that the calculations that form part of this tool are correct and accurate, It has been back-tested and validated against the NASA-TM-X-74335 report. HOWEVER, AeroToolbox cannot and does not guarantee that the results output from the calculator are correct. You should always double check the results – especially if you are using the results for engineering calculations. Finally, if you do discover any bugs in the calculations please send an email to and let me know so I can make the correction.

Disclaimer (the legal version):

Aerotoolbox has made this atmospheric calculator freely available to use by accessing it from the address. Be aware that the content on this site is copyrighted and redistribution or copying of this content is prohibited. The release of this calculator does not and cannot warrant that any functions contained within are accurate or error free. The use of this software comes with NO WARRANTY or LIABILITY of any kind. The entire risk as to the software applicability, performance and quality lies solely with you as the user and not Aerotoolbox. It is the responsibility of the user to ensure that the correct values have been selected at all times and to cross-reference the results with those contained in NASA-TM-X-74335. In no circumstance or event shall, or the domain owner associated with the website, be liable for any damages, whether direct or indirect, incidental, special, or consequential arising out the use of or any defect inherent in the software. By using this calculator, you as the user expressly agree to the terms of this disclaimer in full.