Choose a plan
AmpSizer Premium
From one circuit to the whole panel.
The tables, the calculators, the panel schedule, the job sheet, and CEC mode are all free - permanently, and a free list is a working one. Premium is what a job needs once it outgrows that list: no ceiling on circuits, the printable job document, and export.
What Premium adds
- Save unlimited circuits, past the 4 a free list holds, and put every one of them on the panel schedule
- Printable job document - your job sheet with a job name, site address, prepared-by line, and date on it, ready to print for the crew
- Export your circuit list as JSON or CSV
Weekly, yearly, and lifetime plans are available. The yearly plan works out to the lowest weekly cost, and lifetime is a one-time payment with no renewal. Live prices load below and are what you're charged at checkout.
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. So are your first 4 saved circuits, the panel schedule and job sheet built from them, and CEC mode. No account needed.
What does Premium add?
Three things, and only three: no ceiling on saved circuits, the printable job document (your job sheet with a job name, site address, prepared-by line, and date on it), and JSON or CSV export. Nothing else on the site is behind it.
Is CEC mode premium?
No. It used to be, and that was wrong twice over: it was a paid feature with no page explaining it anywhere on the site, so nobody could find it or want it, and the most important thing it has to say to a Canadian reader is that these are NEC ampacities and CSA C22.1 values differ. That is a warning, and warnings are not for sale. CEC mode and metric conductor sizes is now a free reference page, and the mode is free with it.
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.