Calcium carbide, also known as calcium acetylide, is a chemical compound with the chemical formula of CaC₂. Its main use industrially is in the production of acetylene and calcium cyanamide.^[3]

The pure material is colorless, while pieces of technical-grade calcium carbide are grey or brown and consist of about 80–85% of CaC₂ (the rest is CaO (calcium oxide), Ca₃P₂ (calcium phosphide), CaS (calcium sulfide), Ca₃N₂ (calcium nitride), SiC (silicon carbide), etc.). In the presence of trace moisture, technical-grade calcium carbide emits an unpleasant odor reminiscent of garlic.^[4]

Applications of calcium carbide include manufacture of acetylene gas, generation of acetylene in carbide lamps, manufacture of chemicals for fertilizer, and steelmaking.