Look up abacus in Wiktionary, the free dictionary.

An abacus is a counting frame.

Abacus may also refer to:

• Abacus (architecture), a flat slab forming the uppermost member or division of the capital of a column
• Abacus (journal), a peer-reviewed academic accounting journal
• Abacus school, a type of Renaissance-era Italian trade school
• Logical abacus, an early mechanical digital computer
• Mental abacus, a system involving visualization of an abacus to carry out arithmetical calculations
• Abacus Harmonicus, an ancient diagram showing the structure and placement of the keys of a particular musical instrument
• Operation Abacus, the Canadian military operation to restore vital services if the year 2000 caused disruption

Companies and brands

• Abacus Federal Savings Bank, an overseas Chinese bank in the United States
  • Abacus: Small Enough to Jail, 2016 documentary about the bank, which was the only financial institution to face criminal charges following the subprime mortgage crisis
• Abacus Data, a Canadian polling firm
• ABACUS, an Enterprise Architecture (EA) mapping software tool by Avolution
• Abacus, an imprint of Little, Brown and Company
• Abacus Recordings, a defunct imprint of Century Media Records
• Abacus Jasper's Management Group, owned by chef Kent Rathbun