六十 (liù shí) is the Chinese numeral for 'sixty', formed by combining 六 (liù, 'six') and 十 (shí, 'ten'). In Mandarin’s base-ten number system, multi-digit numbers are constructed additively: 六十 literally means 'six tens', equivalent to 6 × 10 = 60. It functions exclusively as a cardinal number and is used in counting, ages, quantities, measurements, and time expressions (e.g., minutes or seconds).

This numeral follows standard Chinese number formation rules—no 'and' or hyphen is used, unlike English. It appears in formal and informal contexts alike, such as stating someone’s age, describing prices, or giving scores. Unlike English, 六十 never changes form for grammatical agreement and always precedes the noun it modifies (e.g., 六十岁, 六十元). It is also part of larger numbers (e.g., 六百六十 for '660') and common idioms like 六十花甲, referring to a traditional 60-year life cycle.