質量 (Chit-liōng) (質量，應 (Eng)。: mass) 是 (sī)1項 (hāng)物件 (mi̍h-kiāⁿ)包含 (pau-hâm)的 (ê)物質 (bu̍t-chit) (matter) 佮 (kap)能量 (lêng-liōng)。 1項物件的質量毋管 (m̄-koán)佇 (tī)桌為 (toh-ūi)攏 (lóng)相 (sio)siâng，猶 (ah)若 (nā)重量 (tāng-liōng)就 (tō)會 (ē)有 (ū)精差 (cheng-chha)。佇相對論 (siong-tùi-lūn)，不變 (put-piàn)質量 (invariant mass) 對 (tùi)無 (bô)共 (kāng)參考系 (chham-khó-hē) (reference frame) 的觀察者 (koan-chhat-chiá)嘛 (mā)攏相siâng; 毋閣 (m̄-koh)相對 (siong-tùi)質量 (relativistic mass) 就會有精差。佇SI，質量的單位 (tan-ūi)是kg。
