Subbituminous coal is a medium-rank coal intermediate between lignite and bituminous coal, characterized by 42-52% carbon content (dry, ash-free basis) and calorific values of 4,540-6,200 kcal/kg (19-26 MJ/kg).

It appears dark brown to black with a dull to moderate luster, and while lower-rank subbituminous C resembles brown lignite, higher-rank subbituminous A grades appear gray-black and shiny like bituminous coal.

Due to its lower calorific value compared to bituminous coal, larger quantities must be burned to produce equivalent energy, though many power plants have adopted it specifically for its low sulfur emissions profile.

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