Contact
Questions, corrections and requests are all welcome. One person reads this address, so replies are not instant, but every message is read.
Reporting a wrong conversion
This is the message we most want to receive. Please include the page address, the value you entered, the result you were shown and the result you expected. If you have a source for the correct factor — a standards document, a national metrology institute, a published definition — include that too, and the fix goes in much faster.
Every constant on this site comes from a defining authority rather than from another converter; the about page lists the sources.
Requesting a unit or a conversion page
Tell us the unit, the category it belongs to, and where you ran into it. Units used in a real trade, science or region are the ones most likely to be added. Not every pair of units gets its own page — pairs at wildly different scales are left out on purpose — but every unit in the catalog is available in the converter itself.
Accessibility problems
If something here does not work with a screen reader, a keyboard alone, or at a zoom level you need, that is a bug and we want to hear about it. Please say which assistive technology and browser you were using.
Privacy requests
The site holds no personal data about you, so there is usually nothing for us to retrieve or erase. The privacy policy explains what the third-party services on this site collect and how to opt out of them.