Then go to Chaper 9 table 4 Percentage fill charts...as far as Phone company a 25 pair in a 4 inch is a joke.
If you want to do another trades job you have to stop thinking like an electrician and learn how that work is done. The question of LV conduit fill comes up frequently and the replys are always along the lines of "think of a THHN size that is similar and go to chapter 9 of the NEC". I don't know how many times we have said that this is wrong. You may get your cables pulled and they may even work but most likely they are no longer in spec.
-Hal
