Conduit Fill Calculator

Bear Knowledge

About this app

Three codes. One app. Works anywhere, in 28 languages.

Conduit fill for CEC (Canada), NEC (United States) and BS 7671 (United Kingdom), in one app.

Set the percentage of fill. Pick a conduit, pick your conductor, and add multiple gauges of conductors to the same conduit. The conduit resizes as conductors are added, with a visual representation of the fill.

Built by a Red Seal master electrician.

THE TABLES ARE THE POINT

Every value was taken from CEC 2024, NEC 2026 and BS 7671 2026. Checked and double checked for accuracy.

WHAT'S IN IT

• CEC C22.1:24 — Table 9 (9A–9H) and Table 6, every conduit family: EMT, ENT, RMC, flexible metal, PVC, EB1/DB2, RTRC and HDPE in every schedule and DR
• NEC 2026 — Chapter 9, Tables 4 and 5
• BS 7671:2018+A4 — the IET On-Site Guide factor method, with run length and bends
• 53%, 40% and 31% fill, and 60% where it applies
• Metric and imperial
• Mixed pulls — different conductor types in the same pipe

28 LANGUAGES

English, French, Spanish, Portuguese, German, Italian, Dutch, Polish, Romanian, Czech, Hungarian, Turkish, Swedish, Norwegian, Danish, Finnish, Greek, Russian, Ukrainian, Vietnamese, Indonesian, Tagalog, Arabic, Chinese, Japanese, Korean, Hindi and Punjabi — the conduit and conductor names in each one, not just the buttons.

NO SUBSCRIPTION. NO IN-APP PURCHASES. NO DATA COLLECTED.

Nothing to sign up for, nothing sent anywhere, and it works with the phone in airplane mode.

This tool is a calculation aid. Always verify results against the electrical code in force in your jurisdiction.

What’s new

First public release.

Conduit fill calculations in three code standards: CEC C22.1 (Canada), NEC 2026 (United States) and BS 7671 (United Kingdom). Every table is transcribed cell for cell from the printed code book and cross-checked, not generated from a formula.

Works entirely offline. Available in 28 languages.