Voltage Drop Calc NEC

Voltage Drop Calc NEC - professional NEC calculator for electricians. Offline, permit-ready.

NEC voltage drop calculator for electricians, apprentices, and electrical engineers.

Calculate voltage drop instantly using official NEC 2023 Chapter 9 data (Tables 8 and 9). Supports single-phase and three-phase circuits with copper or aluminum conductors. No internet required - works 100% offline on the job site.

FEATURES:

• Single-phase and three-phase calculations
• 5 voltage presets: 120V, 208V, 240V, 277V, 480V
• Copper and aluminum conductors: 14 AWG through 1000 kcmil
• 3 conduit types: PVC, Aluminum, Steel
• NEC Chapter 9 Table 9 effective impedance (Z) at power factor
• Custom power factor support (default 0.85)
• Voltage drop in volts and percentage
• PASS/FAIL indicator based on NEC 3% recommendation
• Recommends minimum wire size to meet 3% threshold
• Shows voltage at load end

NEC REFERENCES:

• NEC 210.19(A) Info Note 4 - Branch circuit: max 3%
• NEC 215.2(A) Info Note 2 - Feeder: max 3%
• Combined feeder + branch: max 5%
• Chapter 9 Table 8 - DC resistance at 75°C
• Chapter 9 Table 9 - AC resistance, reactance, effective Z

PRO FEATURES (one-time purchase):

• No ads
• Save calculation history
• Export calculations as PDF reports
• Dark theme support

BUILT FOR THE JOB SITE: This app is designed by electricians, for electricians. Enter your circuit parameters, see voltage drop instantly, and get a recommended wire size - no complicated menus or unnecessary features.

ACCURATE NEC DATA: All resistance and reactance values are sourced from NEC 2023 Edition, Chapter 9. Effective impedance is calculated using Z = R·cos(θ) + XL·sin(θ) per the NEC method. Always verify calculations against the official NEC code book before installation.

PERFECT FOR:

• Licensed electricians
• Electrical apprentices
• Electrical engineers and designers
• Electrical contractors
• DIY electrical projects
• NEC code exam preparation

OFFLINE & PRIVACY:

• Works 100% offline - no internet needed
• No account required
• No data collection
• Your calculations stay on your device

Simplify your voltage drop calculations on the job site.