About this site

This site is built and maintained by Jeffrey Tepper (Insiviz). It offers 120+ free unit converters that answer instantly, without accounts, ads walls or server round-trips.

Every conversion factor follows the exact international definition of the unit: SI units as maintained by the BIPM, and imperial units as fixed by the 1959 International Yard and Pound Agreement (1 inch = 25.4 mm exactly, 1 pound = 453.59237 g exactly), as published by NIST. Rounding only happens on screen — never in the underlying math.

Found an error or missing tool? Reach out via the contact page — corrections ship within days.