NIST

NIST (National Institute of Standards and Technology) is a US federal agency, part of the Department of Commerce, that develops measurement standards and reference data. Founded 1901 as the National Bureau of Standards; renamed NIST in 1988.

Convertitive cites NIST primarily for unit conversion: the canonical reference is NIST Special Publication 811, Guide for the Use of the International System of Units (SI), which lists every US customary unit (foot, pound, gallon, BTU, horsepower) with its exact SI equivalent. Every imperial-metric factor on the site traces to SP 811.

NIST’s broader role:

• Maintains the US national physical reference standards.
• Publishes FIPS (Federal Information Processing Standards), including the SHA hash family and AES encryption standard.
• Operates atomic clocks contributing to the international UTC reference.
• Publishes reference data for chemistry, physics, materials science.

The international counterpart for unit definitions is the BIPM (Bureau International des Poids et Mesures) in Paris, which publishes the SI Brochure that NIST cross-references. See our units methodology for the full citation chain behind every unit conversion on the site.