Legal

Terms of Service

Last updated: August 5, 2026

These Terms of Service ("Terms") govern your use of VoltageDrop.calc ("the website," "the tool," "we," "us," or "our"). By accessing or using this website, you agree to be bound by these Terms. If you do not agree to these Terms, please do not use this website.

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Engineering Disclaimer — Critical Notice

Calculations provided by this tool are for educational and planning purposes only. They are intended to assist electricians, engineers, and informed DIYers in preliminary wire sizing and circuit design. All electrical installations must comply with local regulations and theNational Electrical Code (NEC), applicable state and municipal codes, and must be verified and approved by a licensed electrician or professional engineer before any installation work is performed. Voltage drop is only one factor in proper wire sizing — ampacity, temperature correction, conduit fill, and applicable code requirements must all be considered. Do not rely solely on this tool for final design decisions.

1. Acceptance of Terms

By accessing VoltageDrop.calc, you confirm that you are at least 18 years of age or the age of legal majority in your jurisdiction, and that you have the legal capacity to enter into these Terms.

2. Description of Service

VoltageDrop.calc provides a free, browser-based voltage drop calculator for electrical circuit design. The tool performs calculations based on NEC Chapter 9 Table 8 (DC resistance) and Table 9 (AC impedance) data. All calculations are performed client-side in your browser — no user data is transmitted to or stored by our servers.

3. Accuracy and Limitations of Calculations

We make reasonable efforts to ensure accuracy, but you acknowledge that:

  • NEC resistance values are provided at 75°C — actual conductor temperatures vary by installation conditions.
  • AC reactance values are approximations based on conduit type; actual values depend on conductor spacing and installation geometry.
  • The tool does not account for voltage regulation, motor starting currents, harmonic distortion, or temperature derating factors.
  • Wire sizing must also account for ampacity ratings per NEC Table 310.12, not just voltage drop.
  • Local amendments to the NEC, jurisdiction-specific codes, and utility requirements may impose stricter limits.
  • Results are not a substitute for professional electrical engineering judgment or licensed electrician expertise.

4. Disclaimer of Warranties

THE WEBSITE AND ITS CONTENT ARE PROVIDED "AS IS" AND "AS AVAILABLE" WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED. TO THE FULLEST EXTENT PERMITTED BY LAW, WE DISCLAIM ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT.

We do not warrant that the calculator results are error-free, complete, or suitable for any specific application. You use the tool at your own risk.

5. Limitation of Liability

TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, VOLTAGEDROP.CALC AND ITS OPERATORS, OWNERS, EMPLOYEES, AND CONTRIBUTORS SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES ARISING FROM:

  • Reliance on calculator results for electrical installations
  • Property damage, equipment failure, fire, or electrical hazards resulting from improper wire sizing
  • Personal injury or death arising from electrical work based on this tool's output
  • Business interruption, lost profits, or economic loss
  • Errors, omissions, or inaccuracies in the provided calculation results

This limitation applies regardless of the theory of liability (contract, tort, strict liability, or otherwise) and even if we have been advised of the possibility of such damages.

6. Indemnification

You agree to indemnify, defend, and hold harmless VoltageDrop.calc and its operators from and against any claims, liabilities, damages, judgments, awards, losses, costs, expenses, or fees (including reasonable attorneys' fees) arising out of or relating to your use of the website, violation of these Terms, or any electrical installations performed based on this tool's output.

7. Intellectual Property

The website's content, design, code, and branding are protected by copyright and intellectual property laws. NEC resistance and impedance data reproduced herein is for educational reference per applicable fair use provisions. NFPA 70 (National Electrical Code) is a registered trademark of the National Fire Protection Association.

8. Acceptable Use Policy

You agree not to:

  • Use automated scraping tools to harvest content from this website
  • Attempt to interfere with or disrupt the website's operation
  • Use the website to provide paid engineering services without appropriate professional licensing
  • Reproduce, distribute, or resell website content without prior written permission

9. Third-Party Links and Services

This website may contain links to third-party websites (including Google AdSense advertisers). We are not responsible for the content, privacy practices, or accuracy of any third-party website. Inclusion of a link does not imply endorsement.

10. Governing Law and Dispute Resolution

These Terms are governed by and construed in accordance with applicable law. Any disputes arising under these Terms shall be resolved through binding arbitration or in the courts of competent jurisdiction. You waive any right to a jury trial in connection with any dispute arising from these Terms.

11. Modifications to Terms

We reserve the right to modify these Terms at any time. Material changes will be reflected by updating the "Last updated" date. Your continued use of the website after any modification constitutes acceptance of the revised Terms.

12. Contact

For questions about these Terms of Service, please visit ourContact page.