Contact

Email

The site is static and has no contact form. Its published contact channel is:

support@rulermeasurements.com

Use this address for the reports and questions described below. A reply and response time are not guaranteed.

Reporting a measurement that looks wrong

The most useful reports let us reproduce what you saw. Please include:

1. Which tool — screen ruler (and which unit tab), image measurement or unit converter, with the page URL.
2. Your device and screen — for example "13-inch MacBook Air, built-in display" or "Samsung Galaxy S23". If it is an external monitor, its model and diagonal size.
3. Browser and version, and whether browser zoom was at 100%.
4. How you calibrated — bank card, screen diagonal, or not at all. The calibration badge above the ruler shows the current method and PPI value; quoting it helps.
5. What you measured and what you expected — for example "a bank card read 88 mm instead of 85.6 mm".

The accuracy page lists the checks worth running before you write, and the methodology page explains what each calibration method assumes.

Corrections to articles

If a dimension, formula or standard quoted in a guide is wrong, send the page URL, the sentence in question and, if possible, a source for the correct value. If a correction is confirmed, the page and its "last updated" date can be revised.

Privacy and advertising questions

Questions about stored data are answered in the privacy policy and the cookie policy. If something there is unclear, email us.

What we cannot help with

We cannot calibrate your screen remotely or certify a measurement. The tools are for everyday use; for anything where an error has legal, medical or financial consequences, use a physical measuring instrument as described in the terms of service.