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Conduit Fill and Size Calculator

Estimate geometric cable area fill, maximum equal-cable count and the minimum circular conduit ID for an entered fill limit.

Inputs

Cable and conduit dimensions

Range: 1–10,000

The model assumes every cable has the same outside diameter and is counted once.

Range: 0.1–500 mm

Use the actual outside diameter of the installed cable, including sheath where applicable. Mixed cable sizes are outside this model.

Range: 0.1–1,000 mm

Use the conduit internal diameter, not nominal trade size or outside diameter.

Range: 0.1–100 %

This is an entered design assumption for the geometric comparison. The calculator does not apply an Australian conduit-fill table or rule; use the applicable project and installation basis.

Result

Entered limit minus calculated fill (%)
-56.00
Geometric area fill (%)
96.00
Maximum count at entered fill limit
2.00
Minimum circular conduit ID at entered limit (mm)
38.73
Result
The entered cable arrangement exceeds the user-selected geometric fill limit. Review the conduit size, cable arrangement and installation basis.

Formula

Calculation logic

Formula definitions and substituted values.

Before relying on the result

  • Estimate fill for cables with a common outside diameter
  • Find the maximum count at a user-entered area-fill limit
  • Use the area comparison as a geometric estimate and verify the applicable installation rules, cable arrangement and pulling constraints separately.

Related calculators

Use the area comparison as a geometric estimate and verify the applicable installation rules, cable arrangement and pulling constraints separately.