A quinceañera traditionally marks the fifteenth birthday, written as XV in Roman numerals.
The Roman numeral XV combines X, which represents 10, with V, which represents 5. Together they equal 15, the age at the center of the celebration. Roman numerals may appear in invitations, cake designs, decorations, jewelry, or event logos.
The use of XV is decorative rather than a requirement of the tradition. Many families write the age as 15, quince, or quince años instead. The celebration’s meaning comes from the birthday milestone and its accompanying customs, not from any particular numeral style.
Roman numerals can sometimes be confused with a formal religious symbol, but XV simply represents the number fifteen. The same numeral is also used in dates, chapter headings, and names unrelated to quinceañeras.