And the thickness of it was an handbreadth, and the brim of it like the work of the brim of a cup, with flowers of lilies; and it received and held three thousand baths. (2 Chronicles 4:5)
In 1 Kings 7:26 the capacity is given as 2,000 baths. It may be that 2,000 baths was the amount ordinarily kept in the tank, but that filled to the brim it would hold 3,000 baths. A bath was 22 liters, about U.S. 5.81 gals. (see on 1 Kings 7:23; Vol. I, p. 167).