Class 2 Wire and Pipe Fill
How many class 2 wires can be installed in a 1 inch emt pipe?? Using 18/2 and 18/3 t-stat wire.
I believe I would try and find the actual dimensions of the cable itself. You may be able to look it up online or contact the manufacturer. Then using Chapter 9 tables you can figure it out. I am not sure those conductors are included in this table but that is what I would use.
Conduit fill does not apply, nor does any chart, other than cross section, in the NEC.
There's basic items that can be figured via circular mils and similar.