BU

BU may stand for:

• Backup
• Brabender Units, a unit of flour analysis measured by a farinograph
• Bethesda unit, a measure of inhibitor activity relating to a coagulation factor
• Biological unit, the smallest number of protein molecules which form a biologically active unit
• Braathens' IATA airline designator
• BU, Brilliant Uncirculated or Beautiful Uncirculated in numismatic coin grading
• Builder (US Navy), a Seabee occupational rating in the U.S. Navy
• Bulgaria's country code
• Burma's ISO3166-3 country code
• Business unit, a division within a company, as in strategic business unit
• BU(n), the classifying space for the unitary group U(n).

Bu may refer to:

• -Bu, a common shorthand for butyl, a functional group in organic chemistry
• Bû, a settlement in France
• bu, a Japanese unit for measuring length equivalent to 3.03 millimeters
• bù a Chinese unit for measuring length equivalent to 1.66 meters
• Bu, a clay pot used as an instrument in traditional Korean music
• Bushel, a unit of capacity