QR

QR may stand for:

Arts and entertainment

• Queensrÿche, a progressive metal band
• Nippon Cultural Broadcasting, a Tokyo radio station, from call sign JOQR
• Queen's Radio, a student radio station at Queen's University Belfast
• Quiet Riot, a heavy metal band

Businesses

• Qatar Airways (IATA code)
• Queensland Rail, a company responsible for the railway system in Queensland, Australia
• Quintana Roo (company), a triathlon-specific wetsuit and bicycle company

Military

• Queen's Rangers, a military unit who fought in the American War of Independence
• Queen's Regulations, a guidance on conduct in the UK's armed forces

Places

• Quintana Roo, a state of Mexico
• Karakalpakstan (Qoraqalpog'iston Respublikasi), Uzbekistan (ISO 3166-2 subcode UZ-QR)

Science, technology, and mathematics

Mathematics

• QR decomposition, a decomposition of a matrix
• QR algorithm, an eigenvalue algorithm using QR decomposition
• Quadratic reciprocity, a theorem from modular arithmetic
• Quasireversibility, a property of some queues
• Reaction quotient (Q_r), a function of the activities or concentrations of the chemical species involved in a chemical reaction

Other uses in science and technology

• QR code (Quick Response code), a two-dimensional code
• ATCvet code QR Respiratory system, a section of the Anatomical Therapeutic Chemical Classification System for veterinary medicinal products
• Nissan QR engine
• Quick release skewer, a device used to secure the wheels on a bicycle

Other uses

• Quarterly Review, a defunct literary and political periodical
• Qatari riyal, the currency of Qatar