Conduit fill calculator

The smallest conduit for a number of same-size wires, using the code fill limits. An estimate: confirm with local code.

Conduit fill

Done.

–Conduits

Need (exact)

Details

How we got it

conduit = smallest with (area × fill limit) ≥ conductors × conductor area

Estimate — confirm with local code and a licensed electrician.

Estimate only — bag yields vary by brand. Check your local building code.

How to use it

  1. Type your measurements. Feet-inch (12' 6 1/2"), decimal feet and metric all work; a bare number means feet or metres.
  2. Need is the exact amount. Buy rounds up to whole bags, sheets or pieces, with the waste % included.
  3. "How we got it" shows the formula, so you can check every number.
  4. A "Check this" note means a value looks unusual. Have a look before you buy.
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