Exit Bag Help

[flyingbird]

I am making my own exit bag now. But i dont get it if i need 40×60 bags or 60×80. The material i am using is ldpe and i try it to do with the ,,doing it with chi..." style.
Could help me please ?
I will use Helium 4.6

I am making my own exit bag now. But i dont get it if i need 40×60 bags or 60×80. The material i am using is ldpe and i try it to do with the ,,doing it with chi..." style.
Could help me please ?
I will use Helium 4.6

And i am going to use 100my thickness and 15l/min Helium