Electrical Engineering Hub
⚡ Why Electrical Engineering Matters in 2026: From residential wiring to industrial power systems, electrical calculations ensure safety, efficiency, and reliability. This pillar page unifies 6 essential electrical engineering calculators — organized by real-world applications: basic electrical theory (Ohm's Law, voltage drop) and power & electronics (power factor correction, LED resistors, battery runtime).
Whether you're an electrician, electrical engineer, electronics hobbyist, or student, these interactive tools provide instant answers: voltage, current, resistance, power, voltage drop, power factor correction, LED resistor values, and battery backup time. Each calculator follows NEC (NFPA 70) and IEEE standards, updated for 2026.
🎯 How to use this hub: Use the live search below to instantly filter calculators. Click any tool to access the interactive calculator, and explore related hubs for Mechanical Engineering, Thermal Engineering, and Unit Converters for a complete engineering ecosystem. All tools are 100% free, no login required.
⚡ Basic Electrical Calculators
Apply Ohm's Law, calculate voltage drop, and analyze single-phase and three-phase power systems per NEC and IEEE standards.
| Calculator / Tool | Focus / Description | Action |
|---|---|---|
| Ohm's Law Calculator V=IR | Calculate voltage (V), current (I), resistance (R), or power (P) in DC circuits. | Coming Soon → |
| Voltage Drop Calculator NEC Chapter 9 | Voltage drop in AC/DC circuits per NEC recommendations (max 3-5%). | Coming Soon → |
| Three-Phase Current Calculator kW/kVA | Line current from power, voltage, and power factor in 3-phase systems. | Coming Soon → |
🔋 Power & Electronics Calculators
Design power factor correction capacitors, calculate LED current-limiting resistors, and estimate battery backup runtime.
| Calculator / Tool | Focus / Description | Action |
|---|---|---|
| Power Factor Correction Calculator Capacitor Sizing | Calculate capacitor kVAR required to improve power factor (PF) to desired value. | Coming Soon → |
| LED Resistor Calculator Current Limiting | Calculate current-limiting resistor value for single or multiple LEDs. | Coming Soon → |
| Battery Runtime Calculator Backup Time | Estimate battery backup time based on capacity (Ah) and load current/power. | Coming Soon → |
📋 Complete Electrical Engineering Toolkit (calculators)
Below you'll find every tool organized in a master reference table. Click any link to access real-time calculations for your next electrical project.
| Post Title | Focus / Short Description | Direct Link |
|---|---|---|
| Ohm's Law Calculator V=IR | Calculate V, I, R, or P in DC circuits | Coming Soon → |
| Voltage Drop Calculator NEC Chapter 9 | Voltage drop in AC/DC circuits (max 3-5%) | Coming Soon → |
| Three-Phase Current Calculator kW/kVA | Line current from power, voltage, power factor | Coming Soon → |
| Power Factor Correction Calculator Capacitor Sizing | kVAR capacitor needed for PF improvement | Coming Soon → |
| LED Resistor Calculator Current Limiting | Resistor value for single or multiple LEDs | Coming Soon → |
| Battery Runtime Calculator Backup Time | Estimate battery backup time (Ah vs load) | Coming Soon → |
📐 Quick Reference — Essential Electrical Engineering Formulas
V = I × R
I = V / R
R = V / I
P = V × I = I² × R = V² / R
Vd = (2 × K × I × L) / CM (single-phase)
Vd = (1.732 × K × I × L) / CM (three-phase)
K = 12.9 (copper), 21.2 (aluminum)
P (kW) = √3 × V × I × PF / 1000
I = P × 1000 / (√3 × V × PF)
PF = P_real / P_apparent
Qc = P × (tan θ₁ - tan θ₂) (kVAR needed)
R_LED = (V_supply - V_LED) / I_LED
Battery Runtime = Ah × V / Load_Power (hours)
🌍 Standard Voltage Levels by Region (2026)
120V / 240V (single-phase)
208V / 480V (three-phase)
Frequency: 60 Hz
230V / 400V (single/three-phase)
Frequency: 50 Hz
230V / 415V (single/three-phase)
Frequency: 50 Hz
100V / 200V (single/three-phase)
Frequency: 50 Hz (East) / 60 Hz (West)
Note: Always verify local standards and NEC/IEC requirements for specific applications.
📏 Common Wire Gauge Ampacity (Copper, 60°C/75°C/90°C)
15A / 20A / 25A
20A / 25A / 30A
30A / 35A / 40A
40A / 50A / 55A
55A / 65A / 75A
70A / 85A / 95A
95A / 115A / 130A
125A / 150A / 170A
Based on NEC Table 310.16. Derate for ambient temperature and conductor bundling.
🧭 Calculator Paths — Find by electrical workflow
⚡ For circuit design & analysis: Ohm's Law → Voltage Drop → Three-Phase Current — complete circuit evaluation.
🔋 Power quality & efficiency: Power Factor Correction → Three-Phase Current → Voltage Drop — improve facility power factor.
💡 Electronics & DIY projects: LED Resistor Calculator → Ohm's Law → Battery Runtime — LED circuit design and portable power.
🔌 Backup power systems: Battery Runtime → Three-Phase Current → Voltage Drop — UPS and generator sizing support.
📐 Students & beginners: Start with Ohm's Law Calculator → Voltage Drop → Battery Runtime — foundation of electrical engineering.
⚠️ Electrical Safety — Important Reminders
These calculators provide engineering estimates for educational and design purposes. Always: follow NEC/NFPA 70 or local electrical codes, use proper PPE (insulated gloves, safety glasses), de-energize circuits before working, verify calculations with licensed electricians, and when in doubt, consult a professional electrical engineer.