Conduit fill vs. ampacity derating: check both
Space in the pipe and allowable current are different limits. Check both before deciding that a pull works.
How to count current-carrying conductors
The number used for heat adjustment is often different from the number used for physical fill.
60°C, 75°C and 90°C termination ratings explained
The wire jacket and the equipment connections place different limits on a circuit.
How many 12 AWG THHN wires fit in EMT?
For physical fill, ½-inch EMT takes 9, ¾-inch takes 16, and 1-inch takes 26 same-size 12 AWG THHN/THWN-2 wires. Ampacity derating is a separate check.