Electrical
Conduit Fill
Check whether THHN conductors fit inside EMT, PVC Schedule 40, or RMC conduit using NEC Chapter 9 fill allowances (53%, 31%, 40%). Supports up to two conductor groups and nipple/sleeve mode (60%).
Safety/code-sensitive estimate. This calculator is not a substitute for licensed professional review, applicable code requirements, manufacturer instructions, field verification, permits, or inspections. Do not rely on this result as the sole basis for work that could affect life safety, fire safety, electrical safety, structural safety, public safety, property damage, code compliance, or required licensure.
Formula: Fill % = total conductor area / conduit internal area — NEC Ch. 9 Tables 1, 4, 5
Conductor Group 1 (THHN)
Conductor Group 2 (optional)