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// ENGINEERING UTILITY

DC CABLE SIZING

Don't guess your electrical safety. Use our engineering-grade calculator to determine the exact cable gauge required for your specific load and distance.

CABLE SIZING TOOL

Engineering Utility v1.0.4

50A
2m

This tool calculates the required cross-section (mm²) based on voltage drop. Safety-critical circuits (chargers, heaters) should target a 1% drop. Always round UP to the nearest available cable size.

Calculated Spec

mm²

Equivalent to 16 AWG

Resistance Factor0.0175 Ω·mm²/m
Total Round-Trip4m

The 3% Rule

Standard van electrical practice allows for a 3% voltage drop. However, for critical systems like battery chargers (DC-DC) or high-wattage inverters, a 1% drop is recommended to prevent efficiency loss and heat buildup.

One-Way vs Round Trip

When calculating distance, we measure the one-way run. Our tool automatically accounts for the return (negative) cable by doubling the length in the resistance equation.

Metric vs AWG

The UK and Europe use metric sizing (mm²), while many components from the US refer to AWG. Our tool provides both to ensure you source the correct engineering standard.