Terms of Service

The short version

VoltDrop is a free set of electrical calculators. The results are estimates for planning — they are not professional engineering advice, and you're responsible for how you use them. Be decent in the comments. That's most of it; the details follow.

1. Accepting these terms

By using voltdrop.app (the "Service"), you agree to these terms and our Privacy Policy. If you don't agree, please don't use the Service.

2. What the Service is — and is not

The Service provides calculators for voltage drop, wire sizing, ampacity, conduit fill, and related electrical estimates, based on commonly used published formulas and tables (such as those in the U.S. National Electrical Code).

The Service is NOT professional advice. Results are simplified estimates for normal conditions. They do not account for every real-world factor (temperature, bundling, derating, continuous loads, local code amendments, equipment listings, and more). The Service is not a substitute for a licensed electrician or professional engineer, and using it does not create any professional relationship.

Electrical work can injure or kill, and mistakes can cause fires. Always verify calculations independently, follow your local electrical code and permit requirements, and hire a licensed professional where required by law or common sense.

VoltDrop sometimes uses a simplified or conservative method. For example, CEC Rule 4-006 limits the termination-temperature requirement to the first 1.2 m of conductor and permits a compliant transition beyond it. VoltDrop does not model that split; it applies the lower of the conductor and termination temperature ratings to the entire run. This is conservative, but it is not the full Code procedure.

Where a Code does not expressly answer an implementation detail, VoltDrop may make a conservative choice that your local inspector or authority may not share. For example, CEC Rule 4-004 does not expressly address installed spare power or lighting conductors; VoltDrop counts them toward Table 5C.

2A. Code editions and local adoption

For U.S. code-based calculations, VoltDrop implements the 2023 edition of NFPA 70 — National Electrical Code (NEC): Table 310.16, Tables 310.15(B)(1) and 310.15(C)(1), 240.4(D), and 110.14(C). Its conduit-fill and box-fill tools also use NEC Chapter 9 Tables 4 and 5 and NEC 314.16, including Tables 314.16(A) and 314.16(B).

For Canadian code-based calculations, VoltDrop implements CSA C22.1:24 — Canadian Electrical Code, Part I, 26th edition (2024): Tables 2, 4, 5A, 5C, and 22, and Rules 4-004, 4-006, 8-102, 8-104, 12-3034, and 14-104.

States, provinces, and municipalities adopt codes on different schedules and may add local amendments. A result that is correct under the edition VoltDrop implements can be wrong where an earlier edition or local amendment applies. You must confirm the edition adopted by your own authority.

3. No warranty

The Service is provided "as is" and "as available," without warranties of any kind, express or implied — including accuracy, reliability, fitness for a particular purpose, and uninterrupted availability. Published standards change; we may lag behind them. We may modify or discontinue any part of the Service at any time.

4. Limitation of liability

To the fullest extent permitted by law, VoltDrop and its operator are not liable for any damages arising from your use of (or inability to use) the Service — including property damage, personal injury, lost profits, or the cost of redoing electrical work — whether based on warranty, contract, tort, or any other theory. If liability cannot be fully excluded, our total liability is limited to $50 (USD). Some jurisdictions don't allow certain exclusions, so parts of this may not apply to you.

5. Comments

You can sign in with Google or Facebook to leave comments. You keep ownership of what you write, but you grant us a worldwide, royalty-free license to display it on the Service. Don't post anything unlawful, hateful, harassing, deceptive, or spammy; no links; no personal information about others; no impersonation. We may remove any comment or suspend commenting access at our discretion, with or without notice. Comment content is other users' opinion, not ours — and comments are never a source of professional electrical advice.

6. Acceptable use

Don't attack, overload, scrape at abusive rates, reverse-engineer for the purpose of harming, or otherwise interfere with the Service, and don't use it in violation of any law.

7. Intellectual property

The VoltDrop name, logo, design, and site content are ours. Published electrical formulas and standards data belong to their respective owners; our presentation of them is what's protected here. Personal, non-commercial use of results (including on jobsites) is exactly what the Service is for — go ahead.

8. Changes to these terms

We may update these terms; the date at the top reflects the latest revision. Continued use after a change means you accept the new terms.

8A. Translated versions

Translations are provided for convenience. If a translated version is inconsistent with the English version, the English version governs.

9. Governing law

These terms are governed by the laws of the United States and the operator's state of residence, without regard to conflict-of-law rules.

10. Contact

Questions about these terms: [email protected].