Per or PER may refer to:

Places

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

(IOC country code) * Pér, a village in Hungary * Perthshire (Chapman code), historic county in Scotland

Science and technology

* Physics education research * Packed Encoding Rules, in computing, an ASN.1 wire format * Per (storm), a January 2007 storm in Sweden

Mathematics

* Rate (mathematics), ratio between quantities in different units * Price–earnings ratio, in finance, a measure of growth in earnings * Player efficiency rating, a measure of basketball player performance * Partial equivalence relation, class of relations that are symmetric and transitive

Science

* Perseus (constellation) (standard astronomical abbreviation) * Period (gene) or ''per'', that regulates the biological clock and its corresponding protein PER * Protein efficiency ratio, of food * PER or peregrinibacteria, a candidate bacterial phyla#Uncultivated Phyla and metagenomics, bacterial phylum

Media and entertainment

* PeR (band), a Latvian pop band * Per (film), ''Per'' (film), a 1975 Danish film

Transport

* Perth Airport (IATA code), in Western Australia * Penrhiwceiber railway station (National Rail station code), Rhondda Cynon Taf, Wales

Other uses

* Per (given name), a Scandinavian form of Peter * Per sign (⅌), a symbol used to indicate a ratio