# Voltbox: Electrician Toolkit

> NEC Calculators & Wire Sizing

Canonical page: [https://chrome-stats.com/d/id6793043903](https://chrome-stats.com/d/id6793043903)

## Overview

- **ID:** `id6793043903`
- **Platform:** Apple
- **Type:** Apple app
- **Status:** Available
- **Publisher:** GABRIELE CHESI
- **Category:** Utilities
- **Version:** 1.1.0
- **Last updated:** 2026-08-10
- **First published:** 2026-07-30
- **Size:** 21 MB
- **Data as of:** 2026-09-18
- **Store listing:** [Apple App Store](https://apps.apple.com/us/app/voltbox-electrician-toolkit/id6793043903)
- **Privacy policy:** [https://privacy.usableutilities.com](https://privacy.usableutilities.com/)

## Description

Fast NEC calculators for electricians. One-time purchase, never a subscription.

Voltbox is a professional calculator toolkit for electricians, built around the NEC (National Electrical Code). Fast, accurate, and yours to own — pay once, keep it forever.

18 CALCULATORS

Fundamentals (free)
• Ohm's Law — voltage, current, resistance, power, series/parallel
• Wire & Cable Sizing — NEC ampacity lookup

Dwelling Load
• Load Calculation — dwelling feeder/service sizing (NEC 220)
• Range Demand — cooking appliance demand load (NEC 220.55)
• Generator Sizing
• Existing Load Evaluation — headroom check for adding new loads to an existing service

Circuit Design
• Voltage Drop — for any run length and load
• Motor / Transformer Sizing — full-load amps per NEC 430
• Grounding & Bonding — NEC 250.66 / 250.122
• EV Charging — NEC 625
• HVAC Circuit Sizing
• Feeder Tap Conductor — NEC 240.21(B)
• Spa Bonding Exemption
• Branch Circuit Sizing

Installation
• Conduit Fill — max conductors per conduit size, including bare wire
• Box Fill — junction box conductor capacity
• Conduit Bending — offset & 90° stub
• Light Meter — jobsite illumination check against OSHA/egress/IES minimums

WHY VOLTBOX
• One-time purchase for Pro — never a subscription, never a recurring fee
• Save and organize calculations by project
• Built for the job site: fast, no clutter, no login screens, works with no signal
• No account required — open the app and start calculating

Ohm's Law and Wire Sizing are free. Unlock Pro once to get every other calculator.

Voltbox is a reference tool based on the NEC. Always verify results against the current code edition adopted in your area and confirm compliance with a licensed electrician or your local inspector before performing any installation.

## Rankings

- #1,351,195 — Overall

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Source: [Chrome-Stats](https://chrome-stats.com/d/id6793043903)