Electrical Cable Size Calculator AC/DC

Calculate cable size for AC/DC, Single/Three Phase, Copper/Aluminum

⚡ Load Input

⚡ Load Value

⚡ System Voltage

🔌 Phase Type

⚡ Power Factor (cos φ) AC only

📏 Cable Length (metres)

🔧 Cable Material

📐 Installation Type

🌡️ Insulation Temp (°C)

📉 Max Voltage Drop (%)

📖 Electrical Cable Size Calculator

This electrical cable size calculator helps you determine the correct cable size for AC and DC electrical systems. It considers load, voltage, cable length, material (copper/aluminum), installation method, and temperature rating.

📐 Cable Sizing Formula

Single Phase AC: I = P × 1000 / (V × PF)
Three Phase AC: I = P × 1000 / (√3 × V × PF)
DC Circuit: I = P × 1000 / V
Voltage Drop: VD = (mV/A/m × I × L) / 1000
VD% = (VD ÷ V) × 100 ≤ 3-5%

📊 Cable Sizing Reference Table

Size (mm²)	Copper (A)	Aluminum (A)	Common Use
1.0	11-15	8-12	Lighting circuits
1.5	14-19	10-14	Lighting, small loads
2.5	20-27	15-20	Socket circuits
4	30-37	22-28	Cookers, showers
6	38-47	29-36	Large loads, EV chargers
10	52-65	40-50	Sub-mains
16	69-87	55-70	Sub-mains, meter tails
25	90-115	75-95	Main tails
35	115-145	95-120	Main supplies
50	140-180	115-150	Large supplies
70	180-225	150-190	Industrial loads
95	220-275	190-230	Industrial loads
120	255-315	215-270	Heavy industrial

❓ Frequently Asked Questions

AC vs DC cable sizing? ▼

AC and DC sizing are similar, but AC systems consider power factor (PF). DC systems use I = P/V directly. Voltage drop calculation is the same for both.

Copper vs Aluminum cable? ▼

Copper has higher conductivity (carries more current for same size) and is more durable. Aluminum is cheaper and lighter but requires larger cable sizes for the same current.

What is voltage drop? ▼

Voltage drop is the reduction in voltage along the cable. It should not exceed 3% for lighting and 5% for power circuits in most standards.

Single phase vs three phase? ▼

Single phase uses 2 wires (live + neutral) at 230V. Three phase uses 4 wires (3 live + neutral) at 400V. For the same power, three phase current is √3 times lower.