Same Scenario. Four Standards. Different Answers.
Real-world circuits calculated across AS/NZS 3008, BS 7671, IEC 60364, and NEC — side by side.
7 Best Cable Sizing Calculators Compared [2026]
An honest, side-by-side comparison of the 7 best cable sizing software tools in 2026: ECalPro, jCalc, ELEK Cable Pro, ElectricalOM, ClearCalcs, PowerCalc, and Excel spreadsheets.
ECalPro vs ClearCalcs [2026 Comparison]
ECalPro vs ClearCalcs: electrical specialist vs multi-discipline platform. Compare cable sizing, standards coverage, pricing, and which is better for electrical engineers.
ECalPro vs ELEK Cable Pro [2026 Comparison]
A detailed, honest comparison of ECalPro and ELEK Cable Pro for cable sizing, arc flash, and protection coordination. Standards coverage, pricing, features, and when to choose each tool.
Cable Sizing: Calculator vs Excel — 7 Reasons to Switch
The hidden risks of cable sizing in Excel: no audit trail, formula errors, no standard updates. 7 concrete reasons why engineering firms are switching to purpose-built calculators.
Best ElectricalOM Alternatives [2026]
Looking for ElectricalOM (myCableEngineering) alternatives? Compare tools that offer AS/NZS, NEC, offline mode, and broader calculator coverage beyond BS 7671 and IEC.
Free Electrical Engineering Calculators — Complete List [2026]
A comprehensive, categorised list of every free electrical engineering calculator available online in 2026. Cable sizing, voltage drop, arc flash, motor sizing, conduit fill, and more.
Best jCalc Alternatives for Cable Sizing [2026]
Looking for jCalc alternatives? Compare 5 cable sizing tools that offer what jCalc doesn't: multi-standard support, offline mode, free tiers, and NEC compliance.
Cable Derating in Hot Climates: 50C Ambient -- Who Suffers Most?
A 100A circuit at 50C ambient: AS/NZS uses a 40C reference while BS 7671, IEC, and NEC use 30C. The 10-degree difference produces different cable sizes.
Conduit Fill: Same 12 Circuits, 4 Standards -- Who Needs the Bigger Conduit?
12 circuits of 2.5mm2 copper in one conduit. NEC, AS/NZS, BS 7671, and IEC all agree on 40% fill -- but different cable ODs produce different conduit sizes.
Demand Diversity: 100-Unit Apartment Block -- Same Building, 4 Different Maximum Demands
A 100-unit apartment block with 850kW installed load. Four standards produce transformer sizes from 315kVA to 500kVA -- a six-figure cost difference.
Earth Fault Loop Impedance — BS 7671 vs NEC Comparison
Compare earth fault loop impedance requirements between BS 7671 and NEC. Side-by-side analysis with calculation examples. Free engineering guide.
Protection Coordination: Same Cascade, Different Discrimination Rules
A 63A MCCB upstream of a 32A MCB with a 10kA fault. IEC calls it discrimination, NEC calls it selective coordination -- and only NEC mandates it for emergency systems.
Arc Flash PPE: The Same MCC Panel — Where All Standards Converge on IEEE 1584
Arc flash is the one calculation where all four standards point to the same method — IEEE 1584. But PPE categories, working distances, and labelling requirements still differ. Here's how.
Cable Derating: 12 Cables in a Tray at 40°C — NEC's 90°C Advantage
12 cables on a perforated tray at 40°C ambient. All standards apply the same 50% grouping factor — but NEC starts from a 90°C base rating, ending with a smaller cable. Is that safe?
Cable Sizing: The 50m Office Feeder — AS/NZS vs BS 7671 vs IEC vs NEC
Same 100A three-phase load, same 50m cable run, four different standards. See exactly where AS/NZS 3008, BS 7671, IEC 60364, and NEC give different cable sizes — and why.
The Complete Cable Sizing Comparison: Every Factor, All Four Standards
A comprehensive reference comparing AS/NZS 3008, BS 7671, IEC 60364, and NEC across every cable sizing factor: current rating, voltage drop, short circuit, derating, and installation methods.
Earthing Systems: TN-S vs TN-C-S vs MEN — Architectural Differences Between Standards
This isn't just a different number — it's a fundamentally different system design. AS/NZS mandates MEN (TN-C-S), BS 7671 prefers TN-S, IEC allows everything, and NEC uses solidly grounded. The implications are enormous.
Maximum Demand: The 20-Unit Apartment Block — 14% Gap Between Standards
20 apartments at 10kW each. NEC says 95kW design load. IEC says 115kW. That 14% gap changes your transformer size, main switch rating, and project cost.
Motor Starting: The 75kW Pump — Why Fuse Selection Changes Between Standards
A 75kW DOL motor start across four standards. Same motor, different fuse sizes, different protection coordination — because fuse characteristics are not universal.
Short Circuit Withstand: The Distribution Board Feeder — k=115 vs k=143
A 50mm² cable, 10kA fault, 0.4s clearing time. BS 7671 and IEC say FAIL with k=115 while AS/NZS says PASS with k=143. Understanding why could save your design.
Voltage Drop: The 100m Workshop Cable — NEC's 3% Rule vs the World
A 32A single-phase cable run across a 100m workshop. NEC flags it as non-compliant at 3%, while BS 7671 and AS/NZS pass it at 5%. See why voltage drop limits matter more than you think.
ECalPro vs Excel: Why Engineers Are Moving to Cloud Calculators
Compare Excel cable sizing spreadsheets with ECalPro's cloud-based calculator. Learn why engineering firms are switching from fragile spreadsheets to verified online tools.
Product Comparisons
How ECalPro compares to other electrical engineering tools.
ECalPro vs ETAP: Cloud vs Desktop Electrical Engineering Software
Cloud-native SaaS vs enterprise desktop suite. Pricing, standards, accuracy compared.
ECalPro vs jCalc.net: Multi-Standard Electrical Calculator Comparison
Standards coverage, calculator modules, pricing, and accuracy compared.
Best Arc Flash Calculators Online (2026)
IEEE 1584-2018 compliant tools compared. Free vs paid, accuracy, PPE output.
Cable Pulling Calculator: ECalPro vs ELEK
Feature-by-feature comparison of cable pulling calculators.
New to electrical standards?
Start with our step-by-step worked examples — real incident-based scenarios with full calculation walkthroughs and standard clause references.
View all 25 worked examples