# Box Fill Calc NEC — NEC Art.314 Box Volume

> NEC Art.314 Box Volume (iPhone/iPad app by Rizvan Adzhoian.)

- Source: https://appshunter.io/ios/app/box-fill-calc-nec/id6763313013 (this page in markdown: same URL + `.md`)
- Developer: [Rizvan Adzhoian](https://appshunter.io/developer/1891746079)
- Category: Utilities, Business
- Price: $0.99 with in-app purchases
- Age rating: 17+
- Requires: iOS 13.0 · 34 MB
- Languages: English
- Released: 2026-04-24
- Data updated: 2026-07-29
- User reviews in markdown: https://appshunter.io/ios/app/box-fill-calc-nec/id6763313013/reviews.md

## What is Box Fill Calc NEC?

NEC box fill calculator for electricians, apprentices, and electrical engineers.

Calculate box fill volumes instantly using official NEC 2023 Article 314.16 data (Tables 314.16(A) and 314.16(B)). No internet required - works 100% offline on the job site.

FEATURES:
- All 24 standard metal box sizes from Table 314.16(A): Device 3x2 and 4x2-1/8 (handy box), Round/Octagonal, Square 4", Square 4-11/16", Masonry, FS, FD
- Custom volume entry for non-standard boxes
- Conductor sizes: 18 AWG to 6 AWG per Table 314.16(B)
- Internal cable clamps, fixture studs, and hickeys
- Multi-gang device fill calculation
- Equipment grounding conductors (EGC) with NEC 2023 rules
- Isolated grounding conductors - separate allowance
- Visual PASS/FAIL indicator with fill percentage
- Shows minimum box volume needed when over-filled
- Suggests a standard box that will pass

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. The interface is clean, fast, and works with one hand. Add conductors, check your fill, and move on - no complicated menus or unnecessary features.

ACCURATE NEC DATA:
All box volumes are sourced from NEC 2023 Table 314.16(A). Conductor volume allowances follow Table 314.16(B) exactly. Fill rules follow Article 314.16 for conductors, clamps, support fittings, devices, and grounding conductors. Always verify calculations against the official NEC code book before installation.

NEC 314.16 FILL RULES:
- Each conductor: volume from Table 314.16(B) based on AWG size
- Internal clamps: 1× largest conductor volume (all clamps combined)
- Support fittings: 1× largest conductor per fitting type
- Devices: 2× largest conductor per gang
- EGC (≤4): 1× largest EGC volume
- EGC (>4, NEC 2023): 1/4 allowance per additional conductor
- Isolated grounds: counted separately

PERFECT FOR:
- Licensed electricians
- Electrical apprentices
- Electrical engineers and designers
- Electrical contractors
- DIY electrical projects
- NEC code exam preparation (Journeyman & Master)

OFFLINE & PRIVACY:
- Works 100% offline - no internet needed
- No account required
- No data collection
- Your calculations stay on your device

Simplify your box fill calculations on the job site.

## Pricing and in-app purchases

Base price: $0.99.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Pro Unlock | $2.99 | one-time |



## Version history (last 5 releases)

### 1.0.9 — 2026-06-10

What's new:
• Complete NEC Table 314.16(A) catalog — added 4x2-1/8 device boxes (handy box): 10.3, 13.0, 14.5 cu.in. All 24 standard metal box sizes covered
• Fixed EGC fill per NEC 2023 314.16(B)(5): each EGC beyond 4 now adds a 1/4 volume allowance

Thanks for using ElecTools! Send feedback to support@tradetools.dev.

### 1.0.8 — 2026-05-18

What's new:
• Moved to tradetools.dev — new umbrella site for all our trade calculators
• Updated support email: support@tradetools.dev
• Refreshed privacy & support pages with unified design
• Bug fixes and stability improvements

Thanks for using ElecTools! Send feedback to support@tradetools.dev.

### 1.0.7 — 2026-04-29

What's new:
• Moved to tradetools.dev — new umbrella site for all our trade calculators
• Updated support email: support@tradetools.dev
• Refreshed privacy & support pages with unified design
• Bug fixes and stability improvements

Thanks for using ElecTools! Send feedback to support@tradetools.dev.

### 1.0.6 — 2026-04-26

Privacy & ad consent update:

- Updated ad consent flow to comply with Google AdMob's latest privacy requirements
- Added "Manage Ad Privacy" option in Settings so users in the EU and UK can review or change their consent at any time
- Improved ad initialization stability and App Tracking Transparency handling
- Minor performance and reliability fixes

### 1.0.5 — 2026-04-25

Cross-promotion improvements: links to other Electools apps now open in App Store on iOS instead of Google Play.

Bug fixes and stability improvements.

## More apps by Rizvan Adzhoian

- [Conduit Fill Calculator-NEC](https://appshunter.io/ios/app/conduit-fill-calculator-nec/id6761846849)
- [Electrical Load Calc NEC](https://appshunter.io/ios/app/electrical-load-calc-nec/id6763250945)
- [Transformer Calc NEC](https://appshunter.io/ios/app/transformer-calc-nec/id6763311943)
- [Voltage Drop Calc NEC](https://appshunter.io/ios/app/voltage-drop-calc-nec/id6763312448)
- [Grounding Size Calc NEC](https://appshunter.io/ios/app/grounding-size-calc-nec/id6763312724)
- [Breaker Size Calc NEC](https://appshunter.io/ios/app/breaker-size-calc-nec/id6763312865)

All apps by Rizvan Adzhoian: https://appshunter.io/developer/1891746079

## Related topics

[electrical box fill calculator](https://appshunter.io/ios/topics/electrical-box-fill-calculator)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-29.*