New calculator available at:

http://www.pipeflowcalculations.com/gasflow/

Calculator is for flow rate or pressure drop calculation of gas that flows through round closed pipe. Isothermal gas flow rate and pressure drop calculator is for any gas including air, natural gas, carbon dioxide, oxigen, nitrogen, or any other gas. Temperature of the gas is considered to be constant.

Isothermal gas flow rate and pressure drop calculator can be used for laminar and turbulent flow regime as Reynolds number is calculated also. You can calculate pressure drop or flow rate through a pipe including friction losses and minor pressure losses calculation.

Isothermal gas flow rate and pressure drop calculation is based on the pressure drop equation for isothermal flow. For pressure loses friction factor f and resistance coefficient K is used. Flow mean velocity for known flow rate and pipe diameter is calculated on the pipe start and on the pipe end. Values of Reynolds number and flow regime - laminar or turbulent are also presented. Pressure difference due to change of height is not included in this version of calculator.