Comparison

Mike Holt's Electrical Toolbox vs Kopperfield

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Mike Holt's Electrical Toolbox

This app provides essential calculations for electricians, inspectors, contractors, and engineers. It helps determine conductor sizing, circuit protection, race sizing, and grounding conductor sizes for various electrical equipment and services.

Highlights
  • Conductor sizing
  • Voltage drop limitations
  • Circuit protection sizing
  • Race sizing
  • Equipment grounding conductor sizing
  • Dwelling-unit service calculations
Features
Read full description

Mike Holt, the industry leader in the electrical industry (MikeHolt.com) has created an amazing, practical and useful app for the electrician, inspector, instructor, contractor and engineer. The app contains conductor sizing (including voltage drop limitations), circuit protection sizing, race sizing, equipment grounding conductor sizing for electric heating equipment (commercial and Residential), air-conditioning equipment (commercial and Residential), motors (commercial and Residential), Transformers (commercial) , and dwelling-unit service calculations and sizing.

About

Kopperfield

Streamline electrical design and permitting with powerful tools for load calculations, panel schedules, and single-line diagrams. Quickly reference the National Electrical Code with an AI-powered chatbot and generate instant PDF reports for inspectors and clients.

Highlights
  • Load calculator with NEC standards
  • Single line diagram tool
  • Panel schedule creation
  • NEC chatbot
  • Instant PDF report generation
  • AI panel photo processing
  • Team dashboard
Features
Read full description

Save time and money. Get ready for permits and projects with faster and easier design tools from Kopperfield, including load calcs, line diagrams, panel schedules, and more. Once logged into your Kopperfield account, you'll enjoy our: * Load calculator: Easy-to-use interface pre-loaded with common appliances and their standard output values from the National Electrical Code. Add information on the property and your calculation will automatically update. Supports both commercial and residential calculations, as well as the Standard (NEC Article 220 Part III), Optional (NEC Article 220 Part IV), and 2026 Standard (NEC Article 120 Part III) methods. * Single line diagram tool: Contains dozens of common templates and electrical symbols to make it easy to generate new diagrams and share them with your team. View diagrams from any device and create new templates on tablet or desktop for your whole team to use. * Panel schedules: Includes tools to complete panel schedules and create labels for electrical panels. Drag-and-drop interface makes it easy to arrange and customize circuits for both split-phase and three-phase projects. * NEC chatbot: Custom chatbot with advanced search capabilities to quickly reference specific sections of the 2017, 2020, or 2023 National Electrical Code. Includes the following features: * Fast PDF outputs: instantly generate a downloadable, one-page PDF report of your load calc, line diagram, or panel schedule to share with inspectors and customers * Smart property data: enter the property address and we’ll pull in the square footage for any customer project or electrical load calculation * AI panel photo processing: upload a photo of an electrical panel to automatically add items to your load calculation or panel schedule * Team dashboard: store your team's projects and documents in one place for easier management, access, and review *Single and three phase options: use a variety of nominal voltages for residential and commercial building types, including: 120/240V, 120/208V, 120/240V, 208Y/120V 3Ø, 240V 3Ø Delta, 240V 3Ø Hi-leg Delta, 347V 3Ø Delta, 480Y/277V 3Ø, 480V 3Ø Delta, 600Y/347Y 3Ø, 600V 3Ø Delta. * Standard scenarios: generate load calcs for scenarios including single family homes (standard and optional methods), multi dwelling units (i.e., duplex, triplex, quad), 120/208v (three-phase power) dwellings, accessory dwelling units and additions, commercial occupancy types, and heat pumps * Common appliance defaults: choose from a pre-loaded list of common appliances and standard output values that you can adjust for every load calculation * EV charger inputs: include EV charger values to any load calculation, essential for modern homes

Screenshots

Mike Holt's Electrical Toolbox4 screens
Kopperfield4 screens

Verdict

The call

The clearest difference is review sentiment: Mike Holt's Electrical Toolbox at 77% against Kopperfield's 0%. Mike Holt's Electrical Toolbox also leads on rating (4.6 vs 3.9) and ratings volume (197 vs 9). Kopperfield's advantage is update cadence (every 3 weeks vs every 3 months). On price, ads, in-app purchases and device support 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Mike Holt's Electrical Toolbox holds the better App Store score, 4.6 against 3.9. That said, the two scores are not equally well evidenced: Mike Holt's Electrical Toolbox has 197 ratings behind it against 9, so its average is the more settled of the two. Written reviews point the same way: 77% of Mike Holt's Electrical Toolbox's written reviews are positive against 0% of Kopperfield's.

UpkeepUpdate frequency

Mike Holt's Electrical Toolbox ships an update every 3 months, Kopperfield every 3 weeks. The most recent releases landed on September 21, 2026 and August 21, 2026 respectively.

Scorecard5 real differences · 5 level
Mike Holt's Electrical Toolbox versus Kopperfield: the parameters behind the verdict, then further details
ParameterMike Holt's Electrical ToolboxKopperfield
PriceFreeFree
Rating4.6 (197 ratings) — better3.9 (9 ratings)
Positive reviews76.7% of reviews — better0.0% of reviews
Number of ratings197 — better9
Update frequencyEvery 3 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterAd-supported
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS14.0 — better15.1
Further details — not scored
Size26 MB45 MB
Age rating4+4+
DeveloperMike Holt EnterprisesKopperfield, Inc.

Customer experience

Mike Holt's Electrical Toolbox

All ratings197 ratings
Positive90.4%
Neutral1.5%
Negative8.1%
Written reviews30 reviews
Positive76.7%
Neutral6.7%
Negative16.7%

Kopperfield

All ratings9 ratings
Positive66.7%
Neutral0.0%
Negative33.3%
Written reviews2 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

Bugs and requests

Mike Holt's Electrical Toolbox

Reported bugs

4 issues
  • Cannot email results
  • Video player widescreen exit bug
  • Previous calculation data not erased
  • App content is outdated

Requested features

6 requests
  • Increase transformer capacity to 225kva
  • Add option to print load calc
  • Update to NEC 2020
  • Add completion system for video series
  • Refine user interface for better usability
Show 1 more
  • Add more features, willing to pay extra

Kopperfield

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Mike Holt's Electrical Toolbox

No in-app purchases

None

Kopperfield

No in-app purchases

Questions

Is Mike Holt's Electrical Toolbox free?
Mike Holt's Electrical Toolbox is free to download, with no in-app purchases.
Is Kopperfield free?
Kopperfield is free to download, with no in-app purchases.
Which has better reviews, Mike Holt's Electrical Toolbox or Kopperfield?
Mike Holt's Electrical Toolbox is rated higher. Mike Holt's Electrical Toolbox averages 4.6 out of 5 from 197 ratings, while Kopperfield averages 3.9 from 9 ratings.
Do Mike Holt's Electrical Toolbox or Kopperfield have ads?
Neither Mike Holt's Electrical Toolbox nor Kopperfield shows ads.
Which is updated more often, Mike Holt's Electrical Toolbox or Kopperfield?
Mike Holt's Electrical Toolbox ships an update every 3 months, and Kopperfield every 3 weeks. Most recently, Mike Holt's Electrical Toolbox was updated on September 21, 2026 and Kopperfield on August 21, 2026.

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