IEC CONDUIT & CABLE DUCT SIZING

IEC Conduit & Cable Duct Fill Calculator

IEC-oriented cross-section screening for round conduits and rectangular cable ducts. Combine cable sizes and quantities, set the internal dimensions and see the scaled fill geometry.

INPUTS

Conduit / cable duct

Use the clear internal dimensions of the actual IEC conduit or cable duct. Choose round or rectangular geometry, enter the manufacturer or project dimensions, and apply the fill limit required by the product, installation system or project specification.

Raceway type

Trade size

IEC sizing basis IEC mode uses the project or manufacturer fill limit; no NEC 53/31/40% rule or nipple allowance is assumed.

CONDUCTORS / CABLES

Fill items

IEC presets use representative H07V-K outside diameters for geometric screening. For release design, select Custom cable and enter the actual manufacturer outside diameter including insulation and sheath.

Result

READY

ACTUAL RACEWAY FILL— %

Automatic standard-size selection: —

Engineering note: Passing the geometric area check does not prove pullability, bending-radius compliance, grouping/thermal performance or product suitability. Verify the applicable IEC installation rules, manufacturer limits and project requirements.

IEC method

IEC does not provide one universal NEC-equivalent fill table for every conduit and duct system:

Use the project or manufacturer fill limit → user-defined

Method: clear internal conduit/duct dimensions × cable outside diameters. The allowable fill percentage is a user-defined project or manufacturer limit; IEC mode does not import NEC Chapter 9 fill percentages.

Why this calculator shows the actual cross-section

The visual uses the cable outside diameter, including insulation and sheath, so the displayed geometry reflects the clear internal space. It is a screening aid and does not replace the applicable IEC product or installation requirements.

1 conductor

Use the applicable IEC project or manufacturer fill limit.

2 conductors

Use the applicable IEC project or manufacturer fill limit.

3 or more

Use the applicable IEC project or manufacturer fill limit.

Geometry and installation limits

The area result and drawing are a geometric screen only. Check the applicable cable duct, conduit, bending radius, grouping, heat dissipation, pulling and manufacturer requirements separately.

Reference basis

IEC installations vary by product and installation system. Use manufacturer dimensions and the project requirements; treat the displayed arrangement as illustrative, not proof of optimal packing or pullability.

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