CableHero

AS/NZS 3008.1.1:2025AS/NZS 3000:2018AS/NZS 5033:2021IEEE 1185-2019

Cable sizing and electrical design, done to the standard.

Calculate cable sizes, voltage drops and maximum demand with precision. Draw the single line diagram, link it to the numbers, and export reports a certifier can sign.

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Experience
10+ yr
Projects
5K+
Free tier
A$0
CableHero cable size calculator

C1 · Main switchboard feeder

25 mm² 4C+E Cu · 2 × 1C

VD 1.31 % · Zs 0.42 Ω · PASS

How It Works

One workflow from load to signed-off report

Start sizing cables, creating SLD drawings and calculating maximum demand in minutes. No complex setup required.

  1. 01

    Size

    Enter the load, run length and installation. The engine applies every derating table, checks voltage drop and fault loop impedance, and picks the smallest compliant cable.

    Learn more: Size
  2. 02

    Draw

    Lay out the single line diagram, link each cable to its calculation, and let the schedule update itself as the design changes.

    Learn more: Draw
  3. 03

    Demand

    Build the maximum demand study with AS/NZS 3000:2018 Appendix C diversity, per phase, and size the mains from it.

    Learn more: Demand
  4. 04

    Report

    Export branded PDF reports, cable schedules and drawings with the full working, ready for the certifier.

    Learn more: Report

Try the engine

Size a cable right now

A quick AS/NZS 3008.1.1:2025 estimate, no account needed. The full cable size calculator is free too, with every derating table, fault loop impedance and protection checks.

Circuit

A
m

An estimate from AS/NZS 3008.1.1:2025 for a single thermoplastic (V-75) multicore cable at 40 °C ambient (25 °C in the ground), with no derating and the worst-case voltage drop at 75 °C. It lets this cable use the whole 5%, which AS/NZS 3000:2018 shares with the consumer mains and submains.

Result

6 mm² copper

230 V single phase, enclosed in conduit

  • Current capacity: 39 A ≥ 32 A
  • Voltage drop: 3.1% ≤ 5%
Recommended size6 mm²
Current capacity39 A
Est. voltage drop7.2 V (3.1%)

For derating, grouping, fault loop impedance and protection checks, use the full calculator: free, no account needed.

Open the full cable size calculatorSave it and get the PDF report

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24 tools, no account needed

Every calculator runs the same engine as the app and cites the clause or table it uses.

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Features

Everything you need for electrical engineering

Cable Sizing

  • AS/NZS 3008.1.1:2025
  • Every Derating Table
  • Voltage Drop & Fault Loop
  • PDF Reports
Learn more: Cable Sizing

SLD Drawings

  • Drag & Drop Editor
  • Professional Symbols
  • Export to PDF/SVG
  • Linked Cable Schedule
Learn more: SLD Drawings

Maximum Demand

  • AS/NZS 3000:2018 Appendix C
  • Diversity Factors
  • Per-Phase Loads
  • Detailed Reports
Learn more: Maximum Demand

One workspace for the whole job

Every tool saves into the same project, so cables, drawings and demand studies stay linked.

Get started free

Why CableHero

Trusted by electrical engineers across Australia

CableHero is designed by electrical engineers, for electrical engineers. We understand your workflow and compliance requirements.

  • AS/NZS 3008.1.1:2025 & 3000:2018 compliant
  • Professional PDF reports
  • Cloud-based and accessible anywhere
  • Regular updates and support

Built on the standards you certify against

AS/NZS 3008.1.1:2025AS/NZS 3000:2018AS/NZS 5033:2021IEEE 1185-2019

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Simple Pricing

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Best for: Minor projects

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Key features

  • 1 project with 50A load limit
  • AS/NZS 3008.1.1:2025 & 3000:2018 compliance
  • Real-time calculation feedback
  • Basic cable sizing tools

Individual

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Best for: Electrical engineers, electricians, designers

A$250/year

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Key features

  • Unlimited projects & loads
  • All tools: cable sizing, SLD drawings, conduit calculator
  • Maximum demand calculator
  • Custom PDF reports with your logo
  • Priority support & updates

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Best for: Teams & organisations

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Key features

  • Everything in Individual plan
  • Team management & collaboration
  • Flexible seat-based licensing
  • Shared projects & calculations
  • Dedicated support

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