Terms of Service

Last updated: September 12, 2026

Using this site

Watts Math provides free calculators for educational and informational use. No account or sign-up is required, and there is no charge to use any page on this site.

Not medical advice

The calculations on this site use standard, published references (NEC conductor resistance and ampacity tables, ENERGY STAR sizing charts, manufacturer appliance wattage tables, NREL PVWatts loss assumptions), not original research or an engineered design. They are planning estimates, not a code-compliant design. Your local electrical code and inspector govern; a licensed electrician or HVAC contractor is responsible for any installation. Do not rely on any number here in place of that.

No warranty

This site is provided "as is," without warranty of any kind, express or implied, including but not limited to accuracy, reliability, or fitness for a particular purpose. Use of any calculator or content on this site is at your own risk.

Limitation of liability

To the fullest extent permitted by law, Watts Math and its operator are not liable for any loss or damage arising from use of, or reliance on, this site or its content.

Advertising

This site may display ads served by Google AdSense and other third-party advertising networks. See the Privacy Policy for details on how those networks use cookies and similar technologies.

Content

The text, design, and code on this site belong to Watts Math unless otherwise noted. You're welcome to link to any page here; please don't republish or scrape the content wholesale without permission.

Changes

These terms may be updated from time to time. Continued use of the site after a change means you accept the updated terms.

Contact

Questions about these terms? Reach out at hello@wattsmath.com.