Il numero romano MDCCCIII nel sistema decimale vale: 1803.
MDCCCIII in latino si scrive mille octingenti tres,
mentre in italiano milleottocentotré.
MDCCLXXXIV, MDCCLXXXV, MDCCLXXXVI, MDCCLXXXVII, MDCCLXXXVIII, MDCCLXXXIX, MDCCXC, MDCCXCI, MDCCXCII, MDCCXCIII, MDCCXCIV, MDCCXCV, MDCCXCVI, MDCCXCVII, MDCCXCVIII, MDCCXCIX, MDCCC, MDCCCI, MDCCCII, MDCCCIV, MDCCCV, MDCCCVI, MDCCCVII, MDCCCVIII, MDCCCIX, MDCCCX, MDCCCXI, MDCCCXII, MDCCCXIII, MDCCCXIV, MDCCCXV, MDCCCXVI, MDCCCXVII, MDCCCXVIII, MDCCCXIX, MDCCCXX, MDCCCXXI, MDCCCXXII