Terms of Use

Last updated: 1 July 2026. By using HardHatMath you agree to these terms. They're short and written to be read.

The service

HardHatMath provides free construction and trade math calculators for general informational use. Tools may be added, changed or removed at any time.

Estimates, not professional advice

Every result is an informational estimate computed from published formulas and code tables. Results are not electrical design, engineering, code-compliance or other professional advice, and no professional relationship is created by using this site. You are responsible for code compliance on your work. Verify results with a licensed professional and with the authority having jurisdiction (AHJ) before acting on them. See the disclaimer for the full picture.

Provided "as is"

HardHatMath is provided "as is" and "as available", without warranties of any kind, express or implied — including accuracy, fitness for a particular purpose, and uninterrupted availability.

Limitation of liability

In plain language: if you rely on a number from this site without verifying it and something goes wrong — a failed inspection, rework, damage, or worse — that is on the person who skipped the verification, not on HardHatMath. To the fullest extent permitted by law, we are not liable for any loss or damage arising from your use of, or reliance on, the site or its calculations.

Acceptable use

Use HardHatMath for lawful purposes only. Don't attempt to disrupt, overload or reverse-engineer the site, or scrape it in ways that harm the service. Calculators may be embedded on other sites using the embed feature we provide, subject to these terms.

Intellectual property

The site's design, text and original content belong to HardHatMath. The NEC is published by the NFPA; this site cites code sections and computes from public formulas — it does not reproduce the code text. You may link to and share our pages freely.

Changes and contact

These terms may be updated from time to time; the current version always lives on this page. Questions? Email [email protected].