19 field calculation tools for systems 600 V and below. Each tool’s page shows it working its own example end to end: every screen, a short video and the PDF report.
In the app’s order. App only: not in the Stinger Pro Suite. App and Suite: also in the Suite, in an older form.
Will the feeder go: tension, sidewall pressure, jamming, the puller, the lubricant and a pull plan PDF.
App and SuiteHow full is the pipe: NEC Chapter 9 fill and the smallest conduit, drawn to scale.
App and SuiteConductor, OCPD, EGC and conduit, with ambient, rooftop, bundling, voltage drop and parallel sets.
App and SuiteFeeder taps under 240.21(B): the rule that applies and every condition, checked.
App onlyService grounding: the main bonding jumper and the GEC to every electrode, each with its section.
App onlyArticle 695: the device that carries locked-rotor current, the conductors, voltage drop, and what stays out of the circuit.
App onlyService conductors, protection, GFPE, the main and supply-side bonding jumpers and the GEC.
App onlyWhere to punch: every hole center dimensioned from the edges, each gap with the rule that set it.
App onlyNEC 314.28 box size for straight and angle pulls, the standard box, and a knockout layout for every wall.
App and Suite20 percent fill, the smallest standard wireway, and the 312.6(A) bending space.
App and SuiteA three-phase motor branch circuit from Table 430.250, on a numbered one-line.
App and SuiteNEC quick reference: neutral counting, OCPD sizing, series ratings, drawings and field testing.
App and SuiteType what you are working on: the 2023 NEC sections to read, with plain-language pointers.
App onlyThe ten UL fuse classes with Littelfuse, Bussmann and Edison series.
App and SuiteCord letters decoded, Table 400.5(A)(1) sizing, and the cord to order.
App and SuiteFLA from kVA and back, and every installation figure from the primary breaker to the GEC.
App and SuiteThe smallest generator for a load, with its breaker, conductors and transfer switch on a one-line.
App and SuitePoint-to-point available fault current through three stages, with the 110.24(A) marking.
App and SuiteConcrete for a duct bank and pole bases, the fit, the spacers and a cross-section to scale.
App and SuiteA motor calculator and a code reference, here in the browser.
Full-load current from Table 430.250, with branch conductor, protection, and grounding.
FLC per NEC Table 430.250 (3-phase induction). Branch conductor at 125% FLC (430.22) from the 75°C copper column; maximum inverse-time-breaker protection at 250% FLC (430.52); EGC per 250.122. Verify motor nameplate and design type.
For estimating and reference only. These calculators are provided as a convenience and demonstration. They do not replace engineering judgment. Always verify against the current adopted edition of the NEC (NFPA 70), manufacturer data, and your local authority having jurisdiction (AHJ) before designing or installing.
The app’s own wording, in full.
Stinger Pro Tools is a calculation and reference tool for qualified electrical professionals. It does the arithmetic and lays out the code references so you don't have to do it by hand, and every result shows its inputs, its working and its sources, so you can check it.
Verify every result, figure and code reference before relying on it - against the code edition adopted in your jurisdiction, the authority having jurisdiction's requirements, and the manufacturer's data. The authority having jurisdiction has the final word.
This app is not a substitute for a licensed engineer's design or seal, or for your own professional judgment.
Provided "as is", without warranty of any kind. To the extent permitted by law, Electrical Ops, Inc. is not liable for any loss or damage arising from its use.
The app shows this when it is first opened, and again from the home screen and the About screen. Every page of every PDF it writes carries this line:
For estimating and planning - verify before relying on it. Not a substitute for a licensed engineer. Based on the 2023 NEC.
The app’s privacy policy, repeated here in full. Its own page, the address filed with Google Play, is stingerprosoftware.com/stinger-pro-tools/privacy.html.
Stinger Pro Tools does not collect, store, sell or share any personal information. There are no ads, no analytics and no tracking of any kind, and the app does not use your location.
Stinger Pro Tools does not have permission to use the internet. Every table and calculation is inside the app, and it works with no signal.
The only check the app makes is to confirm that your Google account has purchased Stinger Pro Tools. The app asks the Google Play Store app on your phone, and the Play Store app confirms the purchase with Google. Nothing about you, your jobs or your phone is sent to Electrical Ops, Inc. Google's handling of that check is covered by Google's own privacy policy. Google Play confirms your purchase when you're connected, at least every 30 days.
support@stingerprosoftware.com
Electrical Ops, Inc., PO Box 49, Ivanhoe TX 75447
Last updated October 2026.
Code edition: Stinger Pro Tools is based on the 2023 National Electrical Code. We're aware the 2026 edition has been published, and that jurisdictions adopt new editions on their own schedules - some already enforce 2026, while many still use 2023 or earlier. Always confirm which edition your jurisdiction enforces. We intend to update the app to reflect the changes in the 2026 code cycle.
For systems 600 V and below.
Every Field Testing and Safety entry in Code Reference carries this label:
Field practice: common-sense, field-proven advice from experienced electricians. Not a code, and not a written safety standard.
Before any electrical work, follow:
Your employer is responsible for providing safety training and procedures. If you don't know your company's procedures, ask before you work.
