This page covers one aspect of conductor work. For the complete free tool (ampacity, voltage drop, conduit fill, and derating together), use our conductor sizing calculator.

Conduit fill calculator

Size raceways with a conduit fill calculator that respects Code raceway fill practice. Ideal when you are bundling conductors in EMT, PVC, AC90, or TECK-style installations and need a clear fill percentage.

Related: Box fill calculator, conduit fill guide, Conductor sizing calculator.

How this calculator works

Enter raceway type and each conductor or cable; the app totals cross-sectional area and compares it to allowable fill for the scenario you select.

Code alignment

Outputs follow the fill logic used for conduit and tubing work. Confirm specific rule selections and any local amendments on site.

Fill and ampacity together

Heavy fill increases bundling derating. The conductor sizing calculator helps you see fill and ampacity in one workflow.

FAQ

How do I calculate conduit fill?

Use conductor and raceway dimensions with the fill rules applicable to your installation. Current Systems automates the geometry and fill percentage so you can size EMT, PVC, AC90, TECK-style runs, and mixed conductor bundles with less table lookup.

Does the tool handle multiple conductors?

Yes. You can combine multiple conductors and cables to see total fill and minimum trade size recommendations based on the inputs you provide.

Is this a substitute for raceway tables in the code book?

The calculator is a workflow aid. You remain responsible for verifying raceway type, derating context, and any project-specific constraints with the adopted electrical code and AHJ.