Il numero romano CDXVIII nel sistema decimale vale: 418. CDXVIII in latino si scrive quadringenti duodeviginti, mentre in italiano quattrocentodiciotto.
CCCXCIX, CD, CDI, CDII, CDIII, CDIV, CDV, CDVI, CDVII, CDVIII, CDIX, CDX, CDXI, CDXII, CDXIII, CDXIV, CDXV, CDXVI, CDXVII, CDXIX, CDXX, CDXXI, CDXXII, CDXXIII, CDXXIV, CDXXV, CDXXVI, CDXXVII, CDXXVIII, CDXXIX, CDXXX, CDXXXI, CDXXXII, CDXXXIII, CDXXXIV, CDXXXV, CDXXXVI, CDXXXVII