'以上' literally combines '以' (yǐ), meaning 'by', 'using', or 'with', and '上' (shàng), meaning 'above' or 'on top'. Together, they form a preposition meaning 'above', 'over', or 'more than', used primarily with numbers, ages, quantities, or ranks to indicate an inclusive upper bound. It is commonly found in formal, written, or administrative contexts — such as official notices, statistics, age requirements, or price ranges — and always follows the number or noun it modifies.

Unlike English 'over', '以上' is inclusive: '18岁以上' means '18 years old and older', not 'older than 18'. It cannot stand alone as a noun or pronoun; it must attach to a preceding numeral or nominal phrase. While occasionally heard in speech, it carries a slightly formal or bureaucratic tone and is rarely used in casual conversation without a quantifier.