Free to check. Paid to file.
The full calculator, all three methods and the on-screen worksheet are free and unlimited. Pay only when you want a formatted permit PDF, saved jobs or your own branding.
Free
- All three NEC methods, 2020/2023/2026
- Step-by-step math
- "What if it fails" options
- Printable on-screen worksheet
- Shareable calculation links
- Unlimited, no account
Homeowner
- Permit-style PDF download, laid out like city worksheets
- Edition, all three methods and disclaimer on the PDF
- One saved house you can update
- Pay once; no subscription
Pro electrician
- Branded PDFs: business name, logo, license #
- Unlimited saved jobs
- Read-only client share links
- Everything in Homeowner
- Cancel any time
Shop
- Up to 5 seats
- Shared job library
- AHJ templates: EVSE at 100%, edition, demand defaults
- Everything in Pro
Prices in USD. Secure checkout by Stripe; we never see your card. You'll create a free account first so your PDFs and jobs have a home. Refund and cancellation policy.
Estimate only; a licensed electrician and your local authority having jurisdiction decide; not an engineering stamp. PDFs never say a panel is "safe"; they show calculated load versus service rating.
Questions
Is the calculator still free?
Yes. All three methods, every edition, the step-by-step math, the fix-it options and the on-screen printable worksheet stay free and unlimited. No account needed.
What does the $9 Homeowner plan include?
A one-time payment, not a subscription. You get a formatted permit-style PDF of the load calculation (inputs, all three methods, the edition used and the disclaimer) and one saved house in your account that you can update and re-download any time.
What do electricians get with Pro?
PDFs with your business name, logo (or text mark) and license number, unlimited saved jobs, and read-only client links to a job result. $19/month, cancel any time.
What is Shop?
Everything in Pro for up to 5 people: a shared job library, AHJ templates (saved local rules such as EV chargers at 100%, a fixed edition, nameplate and demand defaults) applied to any job, and one branding profile. $49/month.
Can I switch or cancel?
Yes. Manage billing in your account lets you switch between Pro and Shop (prorated) or cancel; a cancelled plan runs to the end of the period you paid for. See the refund policy in our terms.
Is a PDF a permit approval?
No. Estimate only; a licensed electrician and your local authority having jurisdiction decide; not an engineering stamp.
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