The invention discloses a multilayer ceramic capacitor and a board having the same mounted thereon. A multilayer ceramic capacitor may include: a ceramic body including dielectric layers and having first and second main surfaces opposing each other, first and second side surfaces opposing each other, and first and second end surfaces opposing each other; an active layer configured to form capacitance by including first and second internal electrodes facing each other with one dielectric layer therebetween and alternately exposed to the first or second side surface; upper and lower cover layersdisposed on and below the active layer; and a first external electrode disposed on the first side surface and a second external electrode disposed on the second side surface.; Thickness T and width Wof the ceramic body satisfy 0.75W!<=T!<=1.25W, gap G between the first and second external electrodes satisfies 30 [mu]m!<=G!<=0.9W, and an average number of dielectric grains in a single dielectriclayer in a thickness direction thereof is 2 or greater.