45 in Roman Numerals
Forty-five is written XLV in Roman numerals. It uses the subtractive rule, where a smaller glyph placed before a larger one is taken away rather than added, which keeps the numeral short and is the part most people find fiddly.
How XLV is formed
Reading left to right, 45 breaks into these additive parts. Each Roman symbol is added in turn to reach the total.
XL + V = 40 + 5 = 45.
Where 45 in Roman numerals is used
- Chapter, act or appendix numbering in books and plays.
- Super Bowl XLV and other numbered championship events.
- Outlines, exam questions and list items in formal documents.
- Monarch and pope names, for example the 45th of a royal line.
Good to know about 45
- Super Bowl XLV was played in 2011; the NFL numbers its championship in Roman numerals (with the one-off exception of Super Bowl 50).
Convert another number
45 is written XLV in Roman numerals.
Frequently asked questions
How do you write 45 in Roman numerals?
Write 45 as XLV, combining XL + V. Start from the largest value that fits and work down until nothing is left over.
Why is 45 not written XXXXV?
XLV uses the subtractive rule: a smaller symbol placed before a larger one is taken away, so you never repeat a symbol four times. XXXXV breaks that rule, which is why XLV is the only correct form.
Which Super Bowl is XLV?
Super Bowl XLV is the 45th Super Bowl, played in 2011. The NFL sets its championship number in Roman numerals, which is why so many people look up values like XLV.
How is XLV broken down?
XLV breaks down as XL (40), V (5), so XL + V = 40 + 5 = 45.