⚡ Cu ρ (75°C): 0.0214 Ω·mm²/m 🔌 NEC / IEC Standards: NFPA 70 & IEC 60364 🇺🇸 US Grid Avg: $0.175/kWh 🇩🇪 DE Grid Avg: €0.345/kWh 🇸🇪 SE Elpris: 1.54 SEK/kWh 🇳🇴 NO Strøm: 1.17 NOK/kWh 🔩 Copper Ref: $9,650/t (2026-10-24)
⚡ IEC 60364-5-52 · DIN VDE · NEK 400 · SS 436 40 00

125 Amp Cable Size at 50 Meters (400V Three-Phase (IEC European Grid))

IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 125 A over 50 m (164.0 ft).

Copper Cable (≤3% Drop)35 mm²Drop: 6.62V (1.65%)
Aluminum Cable (≤3% Drop)70 mm²Drop: 5.46V (1.36%)
Voltage at Load393.4 VLine Loss: 1433.0 W
Max Power & Breaker86.6 kW125A MCB/MCCB

IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 125A at 50m

Cross-Section (mm²)Cu AmpacityAl Ampacity Cu Voltage DropLoad VoltageAl Voltage DropPower LossStatus
1.5 mm²16 A12 A154.44 V (38.61%)245.6 V254.76 V (63.69%)33437.5 WDrop High
2.5 mm²24 A18 A92.66 V (23.17%)307.3 V152.85 V (38.21%)20062.5 WDrop High
4 mm²32 A25 A57.92 V (14.48%)342.1 V95.53 V (23.88%)12539.1 WDrop High
6 mm²41 A32 A38.61 V (9.65%)361.4 V63.69 V (15.92%)8359.4 WDrop High
10 mm²57 A44 A23.17 V (5.79%)376.8 V38.21 V (9.55%)5015.6 WDrop High
16 mm²76 A59 A14.48 V (3.62%)385.5 V23.88 V (5.97%)3134.8 WDrop High
25 mm²101 A78 A9.27 V (2.32%)390.7 V15.29 V (3.82%)2006.2 WDrop High
35 mm²125 A97 A6.62 V (1.65%)393.4 V10.92 V (2.73%)1433.0 W✓ OK (≤3%)
50 mm²151 A118 A4.63 V (1.16%)395.4 V7.64 V (1.91%)1003.1 W✓ OK (≤3%)
70 mm²192 A150 A3.31 V (0.83%)396.7 V5.46 V (1.36%)716.5 W✓ OK (≤3%)
95 mm²232 A181 A2.44 V (0.61%)397.6 V4.02 V (1.01%)528.0 W✓ OK (≤3%)
120 mm²269 A210 A1.93 V (0.48%)398.1 V3.18 V (0.8%)418.0 W✓ OK (≤3%)
150 mm²309 A241 A1.54 V (0.39%)398.5 V2.55 V (0.64%)334.4 W✓ OK (≤3%)
185 mm²353 A275 A1.25 V (0.31%)398.7 V2.07 V (0.52%)271.1 W✓ OK (≤3%)
240 mm²415 A324 A0.97 V (0.24%)399.0 V1.59 V (0.4%)209.0 W✓ OK (≤3%)
300 mm²477 A372 A0.77 V (0.19%)399.2 V1.27 V (0.32%)167.2 W✓ OK (≤3%)
400 mm²570 A445 A0.58 V (0.14%)399.4 V0.96 V (0.24%)125.4 W✓ OK (≤3%)

FAQ — 125 Amp Cable Size at 50 Meters (400V Three-Phase (IEC European Grid))

What mm² cable size is required for 125A at 50 meters (400V)?

According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 35 mm² copper cable for 125A over 50m at 400V (voltage drop: 6.62V or 1.65%).

What is the power capacity of 125A at 400V?

At unity power factor, 125A at 400V supports 86.6 kW with a standard 125A circuit breaker.