LED voltage drop and power-injection calculator
Estimate a conservative DC feeder voltage drop from run length, connected watts per metre, supply voltage, and the actual conductor resistance.
Power-injection estimate
1.43%
0.34 V drop · approximately 23.66 V at the far end
- Total load
- 60W
- Full-load current
- 2.5A
- Feed zones
- 1
- Zone length
- 5m
How this estimate works
Vdrop = (W/m × length ÷ V) × (Ω/km × 2 × length ÷ 1000)
- • Conservative full-load current over the complete outbound and return conductor.
- • Does not include connector loss, temperature rise, inrush, supply tolerance, or data topology.
- • Use the actual product datasheet and cable resistance before procurement or installation.
Use the output as a design-review starting point
Conductor presets use Southwire's published 20°C stranded-copper DC resistance table. Real cable resistance changes with conductor construction and temperature, so the supplier datasheet value should replace the preset whenever possible.
This tool intentionally assumes the full connected load current over the entire loop. It does not determine ampacity, over-current protection, allowable touch voltage, installation method, or regulatory compliance.
Source: Southwire Conductor Sizing Reference Guide. Always verify against the selected cable and applicable code.