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Voltage Drop Calculator

Estimate copper wire voltage drop from length, current, voltage, and AWG gauge.

ft
A
V
Voltage drop
3.176 V
2.65% of supply voltage
Estimated load voltage116.824 V
Wire gaugeAWG 12 copper
Round-trip length100 ft

Uses approximate 20°C copper resistance. Real voltage drop depends on conductor temperature, installation, and applicable electrical code; consult a licensed electrician.

About the Voltage Drop Calculator

Estimate copper wire voltage drop from length, current, voltage, and AWG gauge.

It runs entirely in your browser — nothing you type is sent to a server — and the result updates as you edit the inputs. Estimates are for educational and informational purposes only; see ourdisclaimer.

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