⚡ 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

250 Amp Cable Size at 20 Meters (230V Single-Phase (IEC Europe / UK / AU))

IEC 60364-5-52 metric conductor sizing (mm²), voltage drop, and power loss calculation for 250 A over 20 m (65.6 ft).

Copper Cable (≤3% Drop)120 mm²Drop: 1.78V (0.78%)
Aluminum Cable (≤3% Drop)185 mm²Drop: 1.91V (0.83%)
Voltage at Load228.2 VLine Loss: 445.8 W
Max Power & Breaker57.5 kW250A MCB/MCCB

IEC 60364 Cable Cross-Section Table (1.5 mm² – 400 mm²) for 250A at 20m

Cross-Section (mm²)Cu AmpacityAl Ampacity Cu Voltage DropLoad VoltageAl Voltage DropPower LossStatus
1.5 mm²16 A12 A142.67 V (62.03%)87.3 V235.33 V (102.32%)35666.7 WDrop High
2.5 mm²24 A18 A85.6 V (37.22%)144.4 V141.2 V (61.39%)21400.0 WDrop High
4 mm²32 A25 A53.5 V (23.26%)176.5 V88.25 V (38.37%)13375.0 WDrop High
6 mm²41 A32 A35.67 V (15.51%)194.3 V58.83 V (25.58%)8916.7 WDrop High
10 mm²57 A44 A21.4 V (9.3%)208.6 V35.3 V (15.35%)5350.0 WDrop High
16 mm²76 A59 A13.38 V (5.82%)216.6 V22.06 V (9.59%)3343.8 WDrop High
25 mm²101 A78 A8.56 V (3.72%)221.4 V14.12 V (6.14%)2140.0 WDrop High
35 mm²125 A97 A6.11 V (2.66%)223.9 V10.09 V (4.39%)1528.6 WDrop High
50 mm²151 A118 A4.28 V (1.86%)225.7 V7.06 V (3.07%)1070.0 WDrop High
70 mm²192 A150 A3.06 V (1.33%)226.9 V5.04 V (2.19%)764.3 WDrop High
95 mm²232 A181 A2.25 V (0.98%)227.7 V3.72 V (1.62%)563.2 WDrop High
120 mm²269 A210 A1.78 V (0.78%)228.2 V2.94 V (1.28%)445.8 W✓ OK (≤3%)
150 mm²309 A241 A1.43 V (0.62%)228.6 V2.35 V (1.02%)356.7 W✓ OK (≤3%)
185 mm²353 A275 A1.16 V (0.5%)228.8 V1.91 V (0.83%)289.2 W✓ OK (≤3%)
240 mm²415 A324 A0.89 V (0.39%)229.1 V1.47 V (0.64%)222.9 W✓ OK (≤3%)
300 mm²477 A372 A0.71 V (0.31%)229.3 V1.18 V (0.51%)178.3 W✓ OK (≤3%)
400 mm²570 A445 A0.54 V (0.23%)229.5 V0.88 V (0.38%)133.8 W✓ OK (≤3%)

FAQ — 250 Amp Cable Size at 20 Meters (230V Single-Phase (IEC Europe / UK / AU))

What mm² cable size is required for 250A at 20 meters (230V)?

According to IEC 60364-5-52 ampacity and the 3% maximum voltage drop standard, you need 120 mm² copper cable for 250A over 20m at 230V (voltage drop: 1.78V or 0.78%).

What is the power capacity of 250A at 230V?

At unity power factor, 250A at 230V supports 57.5 kW with a standard 250A circuit breaker.