DC Cable Size Calculator
Enter your values and the calculator will recommend the minimum copper cable size to stay under your voltage drop limit.
Current (A)
Continuous load safety factor
Apply ×1.25 to current
Voltage (V)
One-way Distance
Uses round-trip length internally (2× one-way) for DC.
Units
Max Voltage Drop (%)
Typical targets: 2–3% for critical loads, 3–5% for chargers.
Copper only
Cable recommendations are based on copper conductor resistance.
Results
Enter your numbers above. Results update automatically.
Warning: This tool sizes for voltage drop only. Verify ampacity based on terminations (often 60/75°C),
bundling, ambient temperature, and installation method.