Cable Calculator

Cable Calculator is a fast, offline field tool for electricians, low-voltage technicians, and network cable installers. Three calculators that answer the questions you actually hit on the job (plus your own cable catalog) all on your device, with no account and no internet required.

LENGTH REMAINING
Stop guessing how much is left on a partial box or spool. Enter a cable's full weight, empty (tare) weight, and full length once, then just weigh what you have. Cable Calculator instantly shows the length remaining, the percentage used, and the weight on the scale. Perfect for end-of-day inventory, job planning, and knowing whether that spool will finish the run.

CONDUIT FILL CAPACITY
See how many cables fit a conduit within code fill limits. Pick the conduit type and size, choose your cable, and get the maximum count for one, two, and three-or-more conductors based on NEC Chapter 9, Table 1 (and OESC/CEC Rule 12-910, Table 8). It also flags the jam ratio, warning you when a three-cable pull is likely to jam so you can size up before you fight it in the field.

MINIMUM WIRE GAUGE
Find the smallest AWG that will carry a given current over a run. Cable Calculator checks both ampacity and voltage drop and tells you which one is the limiting factor. Enter the current, one-way run length, system voltage, and allowed voltage-drop percentage; toggle between in-conduit and free-air; and get your answer (copper, DC / single-phase). It even shows the thinner gauge you could use by paralleling conductors (2x, 3x, or 4x) which is handy for long low-voltage runs.

YOUR CABLE CATALOG
Build a library of the cables you actually stock: brand, type, jacket, shielding, packaging, conductor (stranded or solid), weights, and diameter. Search it instantly and reuse entries across every calculator. Import and export your whole catalog as CSV or Excel to back it up or share it with your crew.

BUILT FOR THE FIELD
• Work in feet or meters, pounds or kilograms.
• Fully offline: no account, no sign-in, no network connection.
• No ads, no tracking, no analytics. Your catalog never leaves your device.
• Clean and fast, with the answers up front.

Cable Calculator is a planning aid, not a substitute for the governing electrical code or a qualified professional. Always verify results against your local code and your AHJ.

POWERED BY LOYALTY FORGE
Loyalty Forge is a telecom first: we originate and terminate calls, host cloud PBX phone systems, and interconnect with carriers across Sault Ste. Marie and Northern Ontario. Phone networks run on wire, so we pull and terminate cable too and we built Cable Calculator for the work we do every day.

Website: https://www.loyaltyforge.com/