If you have conductors of different sizes you may want to use Tables 5 and 5A for dimensions of conductors and Table 4 for conduit dimensions to arrive at the correct fill.
hardtoknowme1961...This is one of the most basic questions.How to legally fill a conduit.#1 one needs to know what size the Electrical mettallic tubing is.#2 One needs to have an understanding of derating.What i am trying to say is that typically wiring conduit sizes and overcurrent and wire guages are dependent and interrealated.If you explain what the situation is we can probably help you .With limited information though all we can do is guess.Hope this helps.