Southwire® Voltage Drop Calc vs NEMA Guide
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Southwire® Voltage Drop Calc
Calculate the appropriate wire size for electrical circuits. This tool helps determine wire size based on voltage drop and current carrying capacity, ensuring compliance with NEC ampacity limits.
- Determine wire size for voltage drop
- Calculate voltage drop for conductor runs
- Limit wire size by voltage drop
- Limit wire size by NEC ampacity
- Supports AWG and KCMIL sizes
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Southwire's voltage drop calculator will help you determine the proper wire size for an electrical circuit based on the voltage drop and current carrying capacity of an electrical circuit. Determines wire size to meet specific voltage drop limits or calculates voltage drop for a specific conductor run. When sizing conductors, calculations limits wire size to voltage drop and NEC ampacity. Southwire's Voltage Drop Calculator is designed for applications using AWG and KCMIL sizes only.
NEMA Guide
Quickly identify and cross-reference NEMA plug and receptacle configurations with detailed illustrations and specifications. This tool streamlines the process for electricians and electrical professionals by allowing searches by NEMA number or filtering by various electrical parameters.
- Identify NEMA plug and receptacle configurations
- Search by NEMA number
- Filter by voltage, amperage, phase, poles, wires, and grounding
- View matching configurations instantly
- Over 170 configuration illustrations
- Detailed specifications for each configuration
- Offline data storage
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Use the NEMA Guide app to quickly identify and cross-reference NEMA plug and receptacle configurations—a must-have tool for electricians and electrical professionals on the job. Whether you're trying to identify an unknown plug or need to confirm the right receptacle for a specific application, this app streamlines the process. Simply search by NEMA number or filter by voltage, amperage, phase, poles, wires, and grounding type to view all matching results. With illustrations and detailed specs for each configuration, to save you time and avoid guesswork on-site. Features: - Search by NEMA configuration number. - Filter by voltage, amperage, phase, poles, wires, and grounding. - Instantly view matching plug and receptacle configurations. - Over 170 high-quality configuration illustrations. - Tap to view detailed specs for each configuration. - Cross-reference plugs and receptacles with ease. - Data is stored locally for quick use in the field or on the job-site.
Screenshots
Verdict
The clearest difference is update cadence: NEMA Guide at every 2 days against Southwire® Voltage Drop Calc's every 2 months. NEMA Guide also leads on rating (5.0 vs 4.6). Southwire® Voltage Drop Calc's advantage is ratings volume (1.5K vs 1) and iOS requirement (15.0 vs 17.6). On price, ads, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
NEMA Guide holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Southwire® Voltage Drop Calc has 1.5K ratings behind it against 1, so its average is the more settled of the two.
Southwire® Voltage Drop Calc ships an update every 2 months, NEMA Guide every 2 days. The most recent releases landed on November 6, 2026 and October 30, 2026 respectively.
| Parameter | Southwire® Voltage Drop Calc | NEMA Guide |
|---|---|---|
| Price | Free | Free |
| Rating | 4.6 (1.5K ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 49.1% of reviews | — |
| Number of ratings | 1.5K — better | 1 |
| Update frequency | Every 2 months | Every 2 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 17.6 |
| Further details — not scored | ||
| Size | 10 MB | 23 MB |
| Age rating | 4+ | 4+ |
| Developer | Southwire Company | Red Zepp LLC |
Bugs and requests
Southwire® Voltage Drop Calc
Reported bugs
24 issues- Useless!
- Won't work
- How to use
- Confused
- Bad app
Show 19 moreShow fewer
- Bad
- Not applicable for Residential
- Electrician
- Terrible
- Not working
- What??
- Terrible
- Don't work
- Terrible
- Choice Between AWG and Metric wire Gauge
- Updated app not so simple
- The last version was better
- App
- Terrible
- Voltage drop calculator
- IOS 8
- One flaw
- Worst app ever
- Average
Requested features
2 requests- Motor starting Voltage drop calculation
- Metric wire size options
NEMA Guide
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Southwire® Voltage Drop Calc
No in-app purchases
NEMA Guide
No in-app purchases
Questions
Is Southwire® Voltage Drop Calc free?
Is NEMA Guide free?
Which has better reviews, Southwire® Voltage Drop Calc or NEMA Guide?
Do Southwire® Voltage Drop Calc or NEMA Guide have ads?
Which is updated more often, Southwire® Voltage Drop Calc or NEMA Guide?
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