What pull box dimensions does RacewayIQ estimate?

It estimates required minimum width, height, and depth, then compares those values against proposed box dimensions entered by the user.

Does the pull box tool support multiple rows of conduits?

Yes. The calculator includes single-row and multi-row layout modes with row spacing, fitting allowance, and edge clearance inputs.

Pull Box Sizing Calculator

Conduit Fill Pull Box Sizing Voltage Drop

Disclaimer: RacewayIQ is an informational engineering tool only. All calculations must be independently verified by the user. Do not rely on these results as the sole basis for design, procurement, installation, construction, permitting, or code compliance decisions.

Pull box sizing

Pull Box Sizing

Click a box face, add raceways, choose where the pull goes, and compare the required minimum against a proposed box size.

Project and Proposed Size

ProjectLocationPrepared byDate

Width (in)Height (in)Depth (in)

Conduit layout on each face

Single row / stackAll conduits on a face are checked as one row.Multiple rows / stacksAssign conduit groups to rows and check row stack depth.

Gap between conduits (in)Gap between rows (in)Only applies when multiple rows are selected.End edge clearance (in)Fitting allowance each (in)

Layout allowances are used for the physical face-fit check. Adjust them for actual connectors, hubs, locknuts, and project spacing standards.

View spacing and fitting visual guide

Layout allowance visual

Gap: clear space between adjacent fitting footprints.

End edge clearance: space from the first/last footprint to the box edge.

Fitting allowance: extra footprint around the conduit for installed hardware.

Single row layout

One row

Pull Box

Click a face, then add conduit entries.

Left Face Conduits

Add only what enters this wall of the pull box.

Pull groupTrade sizeQtyGoes toAuto: Straight pull

Pull type guide

Pathing: choose where conductors leave this box. The pull type is classified from the path.

Straight: conductors pass straight through between opposite walls.

Angle: conductors enter one wall and leave through an adjacent wall.

U-pull: conductors enter and leave through the same wall.

Splice: conductors are spliced or terminated inside the box.

Pull Box Result

Governing face: Right

Enter proposed size

Minimum allowable box size

16 in W x 3.50 in H x 3.50 in D

Required width

16 in

Required height

3.50 in

Required depth

3.50 in

Proposed width

Not entered

Proposed height

Not entered

Proposed depth

Not entered

Governing calculation

Right face Straight pull: 8 x 2 in = 16 in

I understand this report is an informational design aid only and must be independently verified before use.Check this box to enable PDF export.

Previous Calculations

Save signed-in calculations, then restore them later with one click.

Pull Box Calculation Breakdown

Minimum allowable size

16 in wide x 3.50 in high x 3.50 in deep

Right face - Straight pull

Dimension checked: width

Conduits counted: 1

Formula: 8 x 2 in = 16 in

Required: 16 in

Left face - Straight pull

Dimension checked: width

Conduits counted: 1

Formula: 8 x 2 in = 16 in

Required: 16 in

Right face opening check

Dimension checked: height

Nominal trade-size total: 2 in

Longest row footprint with allowances: 3.50 in

Stacked row depth: 3.50 in

Proposed height: Not entered

Formula: Right face installed footprint = 2 in trade sizes + 0.5 in fittings + 0 in gaps + 1 in edge clearance = 3.5 in

Left face opening check

Dimension checked: height

Nominal trade-size total: 2 in

Longest row footprint with allowances: 3.50 in

Stacked row depth: 3.50 in

Proposed height: Not entered

Formula: Left face installed footprint = 2 in trade sizes + 0.5 in fittings + 0 in gaps + 1 in edge clearance = 3.5 in

Verify conduit spacing, locknut/bushing clearance, bending space, and raceway-to-raceway separation manually against the adopted NEC and actual layout.

The face-fit check uses entered layout allowances. Confirm actual fitting outside dimensions, locknut/bushing clearances, row spacing, and project spacing requirements.

Code References

NEC 314.28(A)(1)

For straight pulls, the box length shall not be less than eight times the metric designator or trade size of the largest raceway.

Config note: Confirm adopted code edition language and local amendments before construction documents are issued.

NEC 314.28(A)(2)

For angle pulls, U-pulls, and splices, the distance from each raceway entry to the opposite wall is based on six times the largest raceway trade size plus the sum of the other raceway trade sizes on the same wall or row.

NEC 314.28 spacing notes

Raceway-to-raceway and raceway-to-wall spacing requirements depend on layout and require field or drawing verification.