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Wire Gauge / Voltage Drop
Size a DC wire for a voltage-drop target.
Live results
- Minimum gauge for voltage drop only
- 20 AWG
- Conductor cross-section
- 0.51762 mm²
Adjust the circuit
Supply voltage
Load current
One-way wire length
Allowable voltage drop
At the far end of the cable
5 VSupply4.8668 VAt load
2.6647% lost over the loop · 0.13323 W
20 AWG0.51762 mm²
Conductor view is scaled for comparison. Voltage-drop sizing only.
All calculated values
Live results
- Minimum gauge for voltage drop only
- 20 AWG
- Conductor cross-section
- 0.51762 mm²
- Loop voltage drop
- 0.13323 V
- Voltage drop
- 2.6647 %
- Cable power loss
- 0.13323 W
Formula and assumptions
Rloop = ρ × 2L / A · ΔV = I × Rloop · Ploss = I²RloopLow-voltage DC, one-way length with an equal return conductor, solid-equivalent AWG 40–0, at 20°C. Copper ρ=0.017241; aluminum ρ=0.028264 Ω·mm²/m. Smallest area meeting voltage drop only—not a safe ampacity recommendation. Check insulation, temperature, bundling, terminals and applicable wiring rules separately. Not for mains or building wiring.