How do you calculate wire duct fill throughput?

Divide the wireway output completed in a shift by the shift hours for a raw rate, then multiply by efficiency. With 1,200 units over 8 hours at 90%, the raw rate is 150/hr and the effective rate is 135/hr.

What is a good routing efficiency for panel wiring?

Experienced crews on repeat layouts often hold 85-92% once setup and rework are included. New builds, congested lineups or first-article panels can drop below 75% while the layout is being proven out.

Why use effective throughput instead of the raw rate?

The raw 150/hr assumes no fitting, trimming or rework. Scheduling to 150 leaves you short; the 135/hr effective figure is what the crew can repeatably deliver across a full shift.

Does duct fill percentage affect this throughput?

Yes. As slotted duct passes 40-50% fill, dressing conductors gets slower and the routing-efficiency input should drop to reflect the harder, congested work near the end of a panel.

Wire duct throughput vs total wiring time — how do they relate?

This tool gives an hourly rate for the duct-layup portion. Total wiring time also includes terminations, labeling and point-to-point checks, so it will always exceed what the duct-fill rate alone suggests.

Switchgear, Panelboards & Electrical Distribution calculator

Wire Duct Fill Calculator

Wire duct fill throughput measures how much slotted wireway a panel shop actually lays up and dresses per hour once real-world routing losses are factored in. Production planners and lead wiremen use it to schedule panel builds, staff the wiring bench and set realistic cycle times for switchgear and panelboard assemblies. Slotted duct is the backbone of a clean panel layout, and how fast a crew can route, fill and cover it drives the whole wiring phase. The effective figure — not the raw rate — is what belongs on a schedule, because it accounts for the fitting, trimming and rework that never shows up in a napkin estimate.

What this calculator does

Wire duct fill throughput measures how much slotted wireway a panel shop actually lays up and dresses per hour once real-world routing losses are factored in.
Use it when wire duct fill in switchgear, panelboards and electrical distribution is being committed and you need a throughput number you can defend.
It divides completed wire-duct output by shift hours to get a raw hourly rate, then derates it by a routing-efficiency percentage to get realistic effective throughput.

Formula used

Raw wire duct fill = completed output ÷ runtime
Effective wire duct fill = raw throughput × efficiency

Inputs explained

Feet of wire duct laid up per shift:
Assembly shift length:
Wireway routing efficiency:

How to use the result

Use it when scheduling the wiring phase of a panel build, sizing the wireman crew, or setting standard times for repeat switchgear assemblies.
A single efficiency percentage can't distinguish a clean open panel from a dense, congested lineup where fill and dressing slow dramatically as duct fills past 40-50%.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
Industrial electricity averages 8.66 cents per kWh across the U.S. (EIA, Apr 2026), up 5.5% from a year earlier. Energy-intensive steps carry this directly into unit cost.
On-highway diesel averages $4.58 per gallon this week (EIA), trending down over recent periods. Truck tonnage is up 3.4% year over year (ATA via FRED).
The U.S. has 21,668 machinery manufacturing establishments employing about 1,086,146 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate wire duct fill throughput? Divide the wireway output completed in a shift by the shift hours for a raw rate, then multiply by efficiency. With 1,200 units over 8 hours at 90%, the raw rate is 150/hr and the effective rate is 135/hr.
What is a good routing efficiency for panel wiring? Experienced crews on repeat layouts often hold 85-92% once setup and rework are included. New builds, congested lineups or first-article panels can drop below 75% while the layout is being proven out.
Why use effective throughput instead of the raw rate? The raw 150/hr assumes no fitting, trimming or rework. Scheduling to 150 leaves you short; the 135/hr effective figure is what the crew can repeatably deliver across a full shift.
Does duct fill percentage affect this throughput? Yes. As slotted duct passes 40-50% fill, dressing conductors gets slower and the routing-efficiency input should drop to reflect the harder, congested work near the end of a panel.
Wire duct throughput vs total wiring time — how do they relate? This tool gives an hourly rate for the duct-layup portion. Total wiring time also includes terminations, labeling and point-to-point checks, so it will always exceed what the duct-fill rate alone suggests.

Last reviewed 2026-05-12.