This calculator can be used to estimate some of the natural gas properties such as:

- pseudo-critical pressure and temperature,
- gas deviation factor (z-factor), 
- gas density and 
- gas viscosity values of a reservoir. 

It also estimates the down hole pressure of a gas well using two different methods to be able to compare the results. It would be a good iphone companion for a Petroleum Engineer.

As the calculations in the calculator use several published formulas in different books and documents and bears error factors compared to experimental values as explained in the same documents, they should be used only for educational purposes and it does not guarantee the correctness of the formulas either.