‘千吨’ (qiān dūn) literally means ‘thousand tons’ and is used as a unit of mass equal to 1,000 metric tons (1,000,000 kilograms). It is commonly employed in scientific, industrial, and military contexts—especially when discussing large-scale quantities such as grain harvests, steel production, or nuclear weapon yields. The character 千 means ‘one thousand’, and 吨 is the standard Chinese term for ‘ton’ (metric ton, equivalent to 1,000 kg). Together, they form a compound noun that functions as a single measurement unit.

Unlike everyday weight terms like 公斤 (kilogram) or 吨 (ton), 千吨 emphasizes scale and magnitude, often appearing in technical reports, news about infrastructure projects, environmental assessments, or energy output statistics. It is not used for small or personal measurements; you would never say ‘this car weighs two 千吨’. Instead, it conveys macro-level quantity, similar to how English uses ‘kiloton’ rather than ‘thousand tons’ in formal contexts.