Electrical Engineering
Platform
Free Beta Access
⚡ Free during Beta · Account required

Free Engineering Calculators

NEC 2023 and CEC 2024 compliant calculators for everyday electrical engineering tasks — powered by the same engine as the full EEP platform. Create your free Beta account to run any tool below; viewing the layout is open to everyone.

Advisory only. Results require PE review per NEC ASM-007 / CEC Rule 2-030.

Cable Sizing Calculator

FREE-001 — NEC 2023 T310.16 / T310.15(B)(1) / T310.15(B)(2)(a) / 240.4(D) / 110.14(C)
Enter parameters and click Calculate to see NEC conductor sizing results with step-by-step code trace.

Cable Pulling Calculator

FREE-002 — NFPA 70 300.17 / NECA 101
Enter conduit and cable parameters to calculate pull tension, jam ratio, and NFPA 70 300.17 compliance.

Arc Flash Incident Energy

FREE-003 — IEEE 1584-2018 (simplified) / NFPA 70E-2021 T130.7(C)(15)(a)
Enter system parameters to calculate arc flash incident energy, flash protection boundary, and NFPA 70E PPE category.

Maximum Demand Calculator

FREE-004 — NEC Art. 220 / T220.42 / T220.44 / 220.82
Add loads and click Calculate to determine maximum demand, demand factors, and recommended service size per NEC Art. 220.

Protection Coordination Check

FREE-005 — NEC 240.12 / IEEE Std 242 (Buff Book) / NFPA 70E
Enter upstream and downstream breaker ratings with fault current to assess basic selectivity coordination.

All 24 free tools

Each tool runs in-browser. Free Beta account required to view results. NEC 2023 + CEC 2024 dual-standard where applicable.

Cable & Conduit

Cable size calculator
Conductor sizing per NEC T310.16 / CEC T2 + ampacity correction
Voltage drop calculator
3 % branch / 5 % total — NEC 210.19(A) FPN, CEC Rule 8-102
Cable pulling tension
NECA 101 capstan + sidewall pressure + jam ratio
Conduit fill
NEC Ch. 9 Table 1 — 40 % / 31 % / 53 % limits with derate

Load & Demand

NEC load calculation
Art. 220 standard method + optional method (commercial)
Demand factor calculator
T220.42 / T220.44 / T220.55 — receptacles, lighting, kitchen
Maximum demand
Service-entrance demand under CEC Rule 8-200 / 8-202
Panel load schedule
A/B/C phase balance + connected vs demand summary
Distribution board
CSA C22.2 No.29 panelboard + main breaker scaffold

Protection & Fault

Breaker sizing
125 % continuous rule + std OCP rounding (NEC 240.6)
Fault current
Point-to-point I_SC at panels, switchboards, MCCs
Arc flash estimator
IEEE 1584-2018 Lee + NFPA 70E PPE category
Protection coordination
Upstream / downstream selectivity check at fault level
Transformer sizing
kVA selection + primary/secondary protection (NEC 450)

Power Quality

Power factor correction
IEEE 1531 capacitor sizing + utility penalty savings
Power unit converter
kW / kVA / HP / BTU live converter — with motor efficiency

Life Safety & Lighting

Life safety — new design
NFPA 72 + UL 464 + CAN/ULC-S524 system classification
Life safety — retrofit
NFPA 72 + CAN/ULC-S537 retrofit workflow
Lighting design
Lumen method + LPD/ASHRAE 90.1 fixture schedule

Reference & Drafting

Code reference (NEC + CEC)
Article / rule lookup with cross-reference switcher
Equipment library
Wire / breaker / conduit / transformer preset catalog
Single line diagram
IEEE 315 symbol placement + auto-routing preview
Place on drawing
Drop symbols onto a drawing background (PNG/JPG/PDF)
AutoCAD scale converter
Metric ↔ imperial scales + annotative scale picker