Terms of Use

Last updated 7 October 2026. Using this site means accepting what follows. The important part is the engineering disclaimer, so it comes first.

Engineering disclaimer

The calculators on this site are design aids. They are not a substitute for the governing standard, for the manufacturer's specifications, for measurement on installed plant, or for the judgement of a qualified engineer who is accountable for the installation.

Specifically:

• Every model simplifies. Each tool states its own limitations on its page, and those sections exist to be read. They say what the model does not cover.
• Typical values are not your values. Where a figure is a typical or design value rather than one fixed by a standard, it is labelled as such. Substitute the number from your own datasheet or measurement wherever you have one.
• Standards change. Figures here reflect the published standards referenced on each page at the time of writing. Verify against the current edition before relying on them.
• Measurement wins. On cable that is already in the wall or fibre already in the ground, a measured value beats a calculated one every time.

Nothing on this site constitutes professional engineering advice, certification, or a warranty that a design will comply with any standard, code, or regulation. Responsibility for verifying a design, and for the consequences of installing it, rests with the person who installs it.

No warranty

This site and its tools are provided "as is" and "as available", without warranty of any kind, express or implied, including any implied warranty of merchantability, fitness for a particular purpose, accuracy or non-infringement. No guarantee is given that the site will be available, uninterrupted, error-free, or that any result it produces is correct.

Errors are taken seriously and corrected when reported — see contact — but the absence of a known error is not a guarantee of correctness.

Limitation of liability

To the fullest extent permitted by law, the operator of this site is not liable for any loss or damage arising from use of, or reliance on, this site or its tools. That includes direct, indirect, incidental, consequential and special damages, and specifically includes equipment damage, installation rework, project delay, loss of service, lost profit and loss of data, whether or not the possibility of such loss was foreseeable.

Nothing in these terms excludes or limits liability where the law does not allow it to be excluded, including liability for death or personal injury caused by negligence, or for fraud. Consumers retain all rights granted to them by mandatory consumer protection law, which these terms do not affect.

Acceptable use

You may use these tools freely for personal and commercial engineering work, including on paid projects. No attribution is required, though it is appreciated.

You may not scrape the site at a rate that degrades it for others, republish its content or calculation code as your own, or present results from it as certified or warranted by this site.

Intellectual property

The text, design and calculation code on this site belong to its operator. The standards referenced — IEEE, ITU-T, TIA and others — belong to their respective bodies; this site reproduces neither their text nor their tables, and names them so that you can consult the authoritative source. Where a figure is quoted from a standard it is identified, and that identification is not a claim of ownership over it.

External links

Links to other sites are provided for reference. The operator does not control them and is not responsible for their content, accuracy or privacy practices.

Changes

These terms may be updated. The date at the top of this page reflects the current version, and continuing to use the site after a change means accepting it.

Governing law

These terms are governed by Spanish law. Any dispute falls to the competent courts of Spain, without prejudice to the rights a consumer has to bring proceedings in their own country of residence under applicable law.