Terms of Service

Last updated: November 4, 2026

These terms are the rules for using Engineer Underground (engineerunderground.com), operated by Engineer Underground, LLC (“we”, “us”, and “our”), in the Phoenix, Arizona area. By using the site or creating an account you agree to them. If you do not agree, please do not use the site.

The short version

• The calculators, converters, references, and guides are for information. Check results yourself before relying on them, especially for anything involving safety, structures, electrical work, or money.
• Be decent: no abuse, no attacks on the site, no copying the whole library.
• Your account and the things you save in it are yours. You can delete your account yourself at any time from your account page.
• We can change or stop parts of the site, and we are not liable for losses from using it.

Information only, not professional advice

Engineer Underground gives formulas, tables, calculators, and explanations to help engineers, makers, and students. We work to keep them correct, but they can contain mistakes, simplifications, or out-of-date values. Results depend on the numbers you enter, and standards and codes (for example the National Electrical Code, thread and fastener standards, or material data) change and differ by region and application.

Nothing on the site is professional engineering, electrical, legal, safety, or financial advice, and it does not replace the standards, codes, manufacturer data, and licensed professionals your work requires. You are responsible for checking any result before you rely on it, and for how you use it. Please do not use the site as the only basis for decisions that could cause injury, damage, or loss.

Groups and notes

Members can create private groups and post short notes inside them. You are responsible for what you post. Do not post anything unlawful, abusive or hateful, anything that infringes someone else’s rights, personal information about other people, or confidential or proprietary information that belongs to your employer, school or anyone else. A group is not a secure channel: do not post passwords, keys or secrets. A group’s owner can remove members and notes and can delete the group. We may remove a group, a note or an account that breaks these terms or puts people at risk, and we do not review private groups in advance.

Community forum

The community forum is a public place where members help each other. You are responsible for what you post. Please do not post anything unlawful, abusive or hateful, advertising or spam, personal information about other people, material you do not have the right to share, or confidential information that belongs to your employer, school or anyone else. Be careful with advice: members’ answers are their own opinions, we do not check them, and they are not professional advice (see “Information only, not professional advice” above).

You keep ownership of what you write. You give us permission to display it on the site, including in search results and previews, and to keep it as part of the conversation. A new member’s first post is reviewed before it appears. We may hide, edit (for example to remove personal information), move, lock or delete posts and threads, and turn off a member’s posting, at any time and without notice, if they break these terms or put people at risk. You can delete your own posts; if you delete your account, your posts stay without your name.

Accounts

You can use most of the site without an account. To create a free account you give us an email address and a password, or you sign in with Google. Please give accurate information, keep your password private, and tell us if you think someone else has used your account. You are responsible for what happens under your account. You must be at least 13 years old to have one.

You can delete your account yourself at any time from the Privacy tab of your account page (if you have a paid membership, cancel it first so you are not charged again), or ask us to do it (see Contact us). We may suspend or close an account that breaks these terms or puts the site or other people at risk.

My Dashboard and what you save

My Dashboard lets members arrange widgets and save settings, notes, and pictures. What you put there stays yours. You give us permission only to store it and show it back to you so the feature works. Please do not upload anything you do not have the right to use, anything illegal, or anything harmful, and do not store sensitive information such as passwords, payment card numbers, or government ID numbers in your notes. Pictures are limited in size and number, and we may remove content that breaks these terms. Back up anything important: we keep backups, but we cannot promise that saved data will never be lost.

Paid memberships

Some features, such as My Dashboard and an ad-free experience, are part of paid memberships. The price and what each plan includes are shown on the membership page before you pay. Memberships are billed monthly in advance through Stripe and renew automatically until you cancel. New members may be offered a free first month on a paid plan. When it is offered, it is shown on the membership page; a payment card is needed to start, nothing is charged during the free month, and when it ends the plan renews automatically at the price shown unless you cancel first from the Manage billing button on your account page. We send a reminder email a few days before the first charge. The free first month is available once per person, and we may change or withdraw the offer at any time. You can cancel or change your plan at any time from the Manage billing button on your account page; access then continues until the end of the period you have already paid for. We may change prices or plans with advance notice, and a change applies from your next renewal. If a payment fails, we may pause paid features after a short grace period until it is fixed. If you think you have been charged in error, contact us (see below) and we will look into it. Features that are free today may become part of a paid plan in the future, but we will not charge you without your clear agreement.

Store purchases

The store sells apparel and similar items. Prices are in US dollars and may change, and the price you see at checkout is the price you pay, plus shipping. An order is accepted when we send it to be made. Payment is handled by Stripe, and items are made and shipped for us by a fulfillment partner. Shipping, delivery times, returns, replacements, and cancellations are explained in our Shipping & Returns page, which is part of these terms. Product photos are illustrations, and colors may look slightly different on your screen or in real life.

Acceptable use

Please do not:

• break the law, or use the site to harm, harass, or deceive anyone;
• try to break into the site, other people’s accounts, or private areas, or interfere with how the site works (for example by overloading it);
• use bots, scrapers, or other automated tools to copy large parts of the site or its data, or to create accounts in bulk;
• upload viruses, malicious code, or content that infringes someone else’s rights;
• pretend to be someone else, or misuse the sign-up, log-in, or comment features.

Our content and your use of it

The text, design, diagrams, calculators, and code on the site belong to Engineer Underground, LLC or its licensors and are protected by copyright. You may use the site for your own learning and work, link to it, and quote short parts with credit. You may not copy, republish, or sell large parts of it, or build a competing library from it, without our written permission. Standards, product names, and trademarks mentioned on the site belong to their owners.

Ads and other websites

The site is supported by advertising provided by Google and its partners, and some paid plans may remove ads. The privacy policy explains how ads and cookies work. The site may link to other websites and services (such as Google sign-in, weather data, and sources we cite). We do not control them and are not responsible for their content or practices.

No warranty

The site is provided “as is” and “as available”, without promises of any kind, whether express or implied, including that it will be correct, complete, always available, or free of errors or interruptions. We may add, change, or remove features, tools, and content at any time.

Limit of liability

To the fullest extent the law allows, Engineer Underground, LLC and its owners, members, and staff are not liable for any indirect, incidental, special, or consequential losses, or for lost profits, lost data, injury, or property damage, arising from your use of the site or from relying on its content. Where the law does not allow a limit, our total liability for any claim is limited to the amount you paid us in the 12 months before the claim (or $50 if you paid nothing). Nothing in these terms limits rights that the law says cannot be limited.

Ending your use

You can stop using the site at any time. We can suspend or end access to the site or to an account if these terms are broken or to protect the site. The parts of these terms that are meant to continue (such as the disclaimers, the limit of liability, and our rights in our content) continue after that.

Governing law

These terms are governed by the laws of the State of Arizona, USA, without regard to conflict-of-law rules. Any dispute will be handled in the state or federal courts located in Maricopa County, Arizona, unless the law where you live gives you the right to bring a claim somewhere else.

Changes to these terms

We may update these terms. When we do, we will change the date at the top of this page, and for important changes we may also tell members by email. Using the site after a change means you accept the new terms.

Contact us

Questions about these terms, or want your account deleted? Reply to any email we have sent you (such as your welcome email) and tell us what you need. We will respond as soon as we can.