Last updated 16 September 2026
CircuitCalcs is part of ElectricalDocs, which is operated by Elevated Systems LLC, based in Bonney Lake, Washington. Using this site means you accept what is written here. If you do not, please do not use it.
A set of free electrical calculators that show their working. They are an educational reference. They are not a design, not a stamped calculation, not a submittal, and not professional engineering or electrical advice. Using them creates no professional relationship with ElectricalDocs or Elevated Systems LLC.
The calculators are based on the NEC (NFPA 70) 2023 edition. The NEC is not law until a jurisdiction adopts it, and jurisdictions adopt different editions and amend them. Verify every result against the applicable adopted code and your local requirements.
Results depend on the data you enter and on the calculation rules this site implements. Check anything you rely on with a qualified person before you buy material, size a service, or submit anything.
This site is provided as is and as available, without warranties of any kind, express or implied, including any implied warranties of merchantability, fitness for a particular purpose, accuracy, or non-infringement. We do not warrant that the calculators are free of errors, that they reflect any particular code edition or local amendment, or that the site will be available or uninterrupted.
To the fullest extent permitted by law, ElectricalDocs and Elevated Systems LLC are not liable for any loss, damage, cost, rework, delay, injury or claim arising out of your use of, or reliance on, this site or anything calculated by it. You are responsible for your own design decisions and for having them checked by someone qualified to check them.
Some jurisdictions do not allow certain exclusions or limitations, so parts of this section may not apply to you.
CircuitCalcs does not offer contracting services and makes no licensed contracting claim. Publishing a calculator is not an offer to perform electrical work.
NEC and NFPA 70 are the property of the National Fire Protection Association. This site refers to the code by article and role; no NEC text is reproduced here. For the code text, use NFPA's own free online access or a purchased copy.
Use the calculators for their purpose. Do not attempt to overwhelm, scrape at volume, probe or interfere with the service — there is a rate limit, and abusing it degrades the site for other electricians.
We may change these terms or the calculators at any time. The date at the top changes when the terms do.
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