AmpSizer

AmpSizer Premium

From one circuit to the whole panel.

The tables and calculators stay free — permanently. Premium adds what you need once a job has more than one run in it: a panel schedule, a printable job sheet, CEC mode, export, and unlimited saved circuits.

Open your circuitsBrowse the free tables

Choose a plan

Unlock everything

  • Panel schedule builder — every circuit on one sheet with load and phase totals
  • Printable job sheet — conductor, breaker, conduit, and ground for the whole job
  • CEC mode — Canadian Electrical Code terminology and conventions
  • Export your circuit list as JSON or CSV
  • Save unlimited circuits, not just your first 2

Premium plans are launching soon. In the meantime the free tier already covers every published table, every reference page, all four calculators, and your first 2 saved circuits.

Start with the free calculatorsBrowse the tables

Good to know

Questions

What stays free?

Every ampacity table, every per-conductor and per-scenario reference page, and all four calculators — wire size, ampacity lookup with derating, voltage drop, and conduit fill — are free forever, along with your first 2 saved circuits. No account needed.

What does Premium add?

Job-level tooling on top of the free reference: a panel schedule builder with load totals, a printable job sheet the crew can carry, CEC mode for Canadian work, JSON and CSV export, and unlimited saved circuits.

Are any ampacity values behind Premium?

No, and they never will be. Every published table value, every per-conductor page, every breaker pairing, and all four calculators are free. Ampacity is safety-relevant information — putting it behind a paywall would be the wrong call regardless of the business case. Premium sells convenience, not access to safety data.

Which code edition is this?

All figures are transcribed from the 2023 NEC, cited on every page that reports a value. Jurisdictions adopt editions on their own schedule and amend them freely, so confirm which edition applies where you are before relying on anything here.

Is this a substitute for the code book?

No. AmpSizer publishes numeric table data and calculators built on it. It reproduces no code text, and the requirements themselves — including the exceptions and conditions those tables depend on — live in the code document. You need that document to do this work properly.

How is my access stored?

Purchases are handled by RevenueCat and Stripe. An anonymous purchase id is kept in this browser so AmpSizer recognises your Premium access on this device. Keep your receipt email for recovery.

I already subscribed on another browser or device — how do I get Premium here?

Head to Restore access and paste the access code shown on this Premium page (or from your receipt). Premium moves to this browser instantly.

Can I cancel?

Yes. Subscriptions renew automatically and can be cancelled anytime from the link in your receipt email. Lifetime is a one-time payment.

Lost your access code?

Your code is shown on this page whenever you're subscribed here, and it's included in your purchase receipt email. If you can't find it, reply to your receipt email from the address you paid with — your subscription is tied to it and access can be recovered from there.