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CEC Box Fill Calculator

Estimate required box volume for Canadian electrical installations using conductors, bonding conductors, devices, insulated wire connectors, internal clamps, fixture studs, and listed box volume.

Inputs

Built around CEC-style box-fill counting logic. Always confirm with the current Canadian Electrical Code and local authority having jurisdiction.

Conductor Groups

Count insulated conductors entering, leaving, or passing through the box.

Results

Required Box Volume
0.0 mL
Available Box Volume
0.0 mL
Recommended Common Box
-
Box Fill Status
0.0%
Within available box volume.

Breakdown

    Shop Boxes & Covers Shop Wire & Cable Ask Arkco to Verify This Box

    Common Examples

    Box Fill Notes

    Conductors
    Count insulated conductors that enter, leave, or pass through the box. Pigtails originating inside the box generally do not count.
    Devices
    Each flush-mounted device yoke or strap is counted as two conductor allowances.
    Insulated Wire Connectors
    Enter the number of individual insulated wire connectors. The calculator converts them into the proper conductor allowance.
    Bonding Conductors
    Bonding and grounding conductors in the box count together as one allowance based on the largest one present.

    © 2026 Arkco Electrical Supply. This calculator is provided for Arkco customers and may not be copied or republished without written permission.