The article examines the formation of plural in units of measurement derived from monosyllabic units of measurement such as килобайт (kilobyte), мегатон (megaton), киловат (kilowatt). Different dictionaries of recent years indicates that plural can be formed with endings -и and/or -ове. The practice on the Internet is examined. There is a tendency to use the ending -и, which is a system for multisyllabic nouns in Bulgarian language. In some units, the ending -и is established. Only in two units the ending is -ове.
Key words: endings of plural, derived units of measurement
