Tera (symbol: T) is a prefix in the SI system of units denoting 10¹², or 1 000 000 000 000.

• TERA is the Topfree Equal Rights Association.

Confirmed in 1960, it comes from the Greek τέρας, meaning monster.

In computer science tera can sometimes mean 1 099 511 627 776 (2⁴⁰), instead of 1 000 000 000 000 especially when used to prefix the byte, giving a terabyte. To avoid this ambiguity, the term tebibyte has been introduced for 2⁴⁰ bytes, but this is not yet widely used.

See also

• SI prefix
• Binary prefix