Free Trunk & Conduit Sizing, Spreadsheet – Filling Ratio Calculator

Free Trunk & Conduit Sizing Spreadsheet: Accurate cable enclosure sizing is critical to protect conductors, maintain flexibility, and comply with electrical standards. Our Free Trunk & Conduit Sizing Spreadsheet uses the 40% filling‑ratio formula to help you instantly calculate the required trunk or conduit diameter based on cable counts and diameters. Designed for electrical engineers, MEP coordinators, and installers, this Excel tool eliminates guesswork and manual calculations so you can select the right enclosure sizes in seconds.

Key Features

Trunk Sizing Calculator

• Filling‑Ratio Formula N×Ac=F×AtN times A_c = F times A_t where FF=40% occupancy factor
• Inputs
  • Number of cables (N)
  • Cable OD (Dc)
  • Trunk width (W) & height (H)
• Outputs
  • Minimum trunk cross‑section (At)
  • Recommended trunk dimensions

Conduit Sizing Calculator

• Occupancy‑Based Sizing N×Aw=F×AcN times A_w = F times A_c for 40% occupancy
• Inputs
  • Cable OD (Dw)
  • Conduit OD (Dc)
• Outputs
  • Required conduit internal diameter
  • Max cable count per conduit

Cable & Enclosure Tables

• Predefined data for common cable sizes (power, data, telecom)
• Standard conduit and trunk dimension lookup
• Automatic filling‑ratio checks and warnings

Free Trunk & Conduit Sizing: How to Use

1. Download & Open
   • Get the free .xlsx file via the download link.
2. Enter Cable Data
   • Input the number of cables and their overall outside diameters.
3. Select Enclosure Type
   • Choose “Trunking” or “Conduit” mode from the dropdown.
4. Review Calculated Sizes
   • The tool displays minimum width/height for trunking or internal diameter for conduits.
5. Export Results
   • Copy the summary table into your design report or BOQ.

Benefits for Electrical Designers

• Time Savings Automates filling‑ratio calculations, cutting manual effort by up to 80%.
• Error Reduction Built‑in validation flags over‑filled enclosures before installation.
• Standards Compliance Ensures a 40% maximum occupancy in line with IEC/BS EN wiring regulations.
• Procurement & Installation Generates precise sizing tables for purchasing and site installation teams.

Free Trunk & Conduit Sizing: Pro Tips

• Always verify local code requirements—some jurisdictions limit occupancy to 35% for mixed‑cable types.
• Use the cable‑type dropdown to quickly select from common power, control, or telecom cables.
• Cross‑check cable bend radius and spacing for easier pulling and maintenance.
• Combine with our Cable Tray Sizing Calculator for end‑to‑end cable management.

Download & Compatibility

• File Format: .xlsx (Microsoft Excel)
• Compatibility: Excel 2010+, LibreOffice Calc, Google Sheets
• License: Free for commercial, educational, and personal use
• Support: Unprotected input cells; formulas protected to prevent accidental change.