Conduit Fill Calculator
Enter conduit inside diameter and wire outside diameters in one consistent unit; this tool reports geometry only.
A QUICK WALKTHROUGH
How to use this tool
- Enter the conduit inside diameter and your fill limit.
- Add each wire diameter and quantity using the same unit.
- Calculate occupied area, fill percentage, and remaining area.
Pure geometry
The result uses circular cross-sectional areas: π(d/2)² for each wire and the conduit. It does not interpret electrical codes, conductor types, derating, installation methods, or construction safety.
Consistent units
Diameters may use any unit, but conduit and wire diameters must use the same unit. The configurable fill limit is a comparison threshold only.
GOOD TO KNOW
Common questions
Does this determine code compliance?
No. It is a geometric estimate and does not provide code compliance or construction safety guidance.
Can I use millimeters or inches?
Yes. Use the same unit for every diameter.
Can I add different wire sizes?
Yes. Add a separate row for each diameter and quantity.