Voltage Cable Drop Calculator

Voltage Cable Drop Calculator estimates voltage drop on a cable run so the job passes inspection.

Built for electricians in the field:

• One-way length in feet or metres
• AWG 14 through 750 kcmil and metric 1.5–300 mm²
• Copper or aluminum
• DC, single-phase, and three-phase
• 3% branch / 5% feeder guidance
• Live PASS / CAUTION / FAIL
• Next size that holds the limit

The calculation uses the circular-mil method at 75 °C (K 12.9 copper / 21.2 aluminum). Metric sizes convert to circular mils. Power factor is included.

Not a code-authority app. Confirm against the electrical code your inspector uses.

Unlock is a one-time purchase: save named jobs and share a clean inspection card. Restore anytime. No account. Jobs stay on the device.