Ampsheet

Wire Monkey Labs

In-app purchases

About this app

Ampsheet is an electrical design and field reference tool for commercial and industrial work — services, feeders, panels, motors and one-line risers. It runs entirely on your device and cites the article behind every answer.

CALCULATIONS AT THE DESK

Circuit — Conductor sizing against the two-step derate and termination rule, voltage drop with real impedance at power factor, raceway fill, and parallel sets. It shows the derivation, not just the answer.

Loads — FLA, amps, VA or kW at any voltage and phase, with a running tally you build straight off a mechanical schedule. Continuous loads are flagged and sized at 125%.

Motors — Table full-load current, branch protection, overload, disconnect and NEMA starter. Table FLC and nameplate FLA are kept in their separate jobs, because they are not interchangeable.

Panels — Schedules from a six-circuit load center to a four-section switchboard. Phase rotation across sections, load classification rollup, noncoincident handling, and a design review that checks the numbers you entered.

Power — Transformer sizing and primary protection, with available fault current from a complex impedance network rather than a lookup table.

DRAWINGS FROM THE FIELD

Riser — Walk a service and record it as you go. Pick the utility source, then work downstream; the app draws the one-line. A multi-story building is drawn the other way up, as a building riser: floors stacked the way the building stacks them, service at the bottom, feeders climbing. Attach photos, mark gear existing, new or demo, and print the sheet.

The kind of thing it catches: a 25 kW charger at 480 V three-phase draws 30.1 A. That points at a 35 A breaker, and 35 A is wrong — EV supply equipment is a continuous load, so it sizes against 125% of the draw. The answer is 40 A. Ampsheet says so, and cites the article that says so.

WHAT COMES OFF THE PHONE

Panel schedules and riser drawings export as PDF, sized letter or 11 × 17 depending on the drawing. These are for field reference, coordination and RFIs. Every sheet is stamped FIELD NOTES and NOT FOR CONSTRUCTION on its face and carries a disclaimer. Nothing Ampsheet produces is a sealed or approved document.

CODE EDITIONS

NEC 2020, 2023 and 2026, with article numbers translated between them. Article citations and calculated values verified against NEC 2020, 2023, 2026. Local amendments still apply — confirm against the edition adopted in your jurisdiction.

HOW IT WORKS

- No account, no sign-in, no sync — nothing you enter leaves the device
- Works with no signal — every calculation runs on the device
- Everything you enter stays on the device and nowhere else
- One subscription, every feature. No tiers, no add-ons, nothing held back
- No ads, no analytics, no tracking

SUBSCRIPTION

Ampsheet is $5.99 per month or $59.99 per year. Both plans renew automatically until cancelled and include every feature — there is no free tier, no trial and nothing sold separately inside the app. Cancel any time in the Play Store under Payments and subscriptions; you keep access until the end of the period you have already paid for. Anything you have created stays on your device either way.

WHAT IT IS NOT

Ampsheet is a reference and calculation tool. It is not an engineering service, and using it does not create a professional relationship. It does not reproduce the text of any code — it cites article numbers so you can look them up in your own copy. You are responsible for verifying every result before relying on it.

NEC and National Electrical Code are registered trademarks of the National Fire Protection Association. NEMA is a trademark of the National Electrical Manufacturers Association. Wire Monkey Labs LLC is not affiliated with, endorsed by, or sponsored by NFPA, NEMA, or any standards body.

Questions and bug reports: [e-mail]

What’s new

- Settings changes now apply immediately — no restart needed
- The job picker stays above the keyboard when naming or renaming
- Markup: drag a placed mark to move it, long-press to select an older one, delete marks individually
- Panel totals now state minimum feeder ampacity and minimum overcurrent device separately