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Wire-Pull Length Calculator

Add horizontal and vertical route, visible slack percentage, and two termination allowances.

Why it matters: Visible geometry and quantity arithmetic improves field coordination and makes allowances available for review.

User inputs

Enter field measurements

6 inputs
Select I-P or SI units for the entire input set.
ft or mDeveloped horizontal route.
ft or mDeveloped vertical route.
%Visible route allowance.
ft or mFirst end allowance.
ft or mSecond end allowance.

Calculated result

Engineering evaluation

Calculation complete—verify project criteria
Wire-pull length (L_w)136 ft
Route length before allowances (L_r)
120 ft

Engineering interpretation

The entered route and visible allowances require 136 ft of conductor.

Important limitations

  • Field-planning screen only. Contract documents, approved details, manufacturer data, tolerances, waste, safety, and professional judgment remain controlling.

Engineering knowledge center

Understand the calculation—not just the answer

2026-08-07 · Free Library
Governing relationships
L_w=(L_h+L_v)(1+s/100)+A_1+A_2
displayed symbols: L_r
Current substitution

L_w=(100+20)×(1+5/100)+5+5=136.

Calculation sequence

Step-by-step method

  1. Confirm dimensions, formula symbols, unit system, and measurement sources.
  2. Apply the displayed geometry, quantity, or field-control equation.
  3. Review allowances, tolerances, constructability, and governing project requirements.

Equation legend

Inputs and calculated quantities

L_h
Horizontal route length — ft or m
L_v
Vertical route length — ft or m
s
Slack allowance — %
A_1
Termination allowance 1 — ft or m
A_2
Termination allowance 2 — ft or m
L_w
Wire-pull length — ft
L_r
Route length before allowances — ft

Continue the evaluation

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Engineering calculation disclaimer

These engineering tools are provided for educational, preliminary evaluation, field verification, and commissioning support. Results depend on the accuracy of user-entered information and the assumptions stated for each calculation. Every colored status and comparison is a screening indicator only; project criteria, contract requirements, applicable codes, manufacturer instructions, measurement uncertainty, and authorized engineering judgment govern. The tools do not replace project-specific engineering analysis or the judgment of a licensed professional engineer.

Read the full use and limitation statement