Convert numbers to Roman numerals or Roman numerals to numbers instantly. Supports 1-3999 with examples like XIV=14 and MMXXVI=2026.
Use this Roman numeral converter to instantly convert Roman numerals to numbers or numbers to Roman numerals. Enter a value in either direction and get the result immediately — no rules to memorise.
Examples: XIV = 14, XL = 40, MMXXVI = 2026, MCM = 1900, XLII = 42. Reverse: 2024 = MMXXIV, 500 = D, 1999 = MCMXCIX. Supports the standard range 1–3999. Useful for reading movie release years, book chapters, Super Bowl editions, clock faces, and historical dates.
Numbers
Arabic numerals actually originated in India. They are called Arabic numerals because they were introduced to Europe from the Arab world around the 1200s, having been used in India prior to that. Arabic numerals: 1, 2, 3, 4, 5, 6, 7, 8, 9, and 0.
Roman numerals are a numeric system that originated in Ancient Rome, adopted by the Romans from the Etruscans. The original system was modified during the Middle Ages, resulting in the Roman numerals we use today. Roman numerals are based on specific letters of the alphabet assigned numeric values.
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Roman numerals
| Hindu-Arabic numerals | Roman numerals | Latin |
|---|---|---|
| 1 | I | ūnus |
| 5 | V | quīnque |
| 10 | X | decem |
| 50 | L | quīnquāgintā |
| 100 | C | centum |
| 500 | D | quīngentī |
| 1000 | M | mīlle |
Roman Numerals Converter FAQ
How do you read Roman numerals?
Roman numerals use letters: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Add values left to right: III = 3, VIII = 8, XII = 12, XVI = 16. Subtract when a smaller value precedes a larger: IV = 4 (5−1), IX = 9, XL = 40, XC = 90, CD = 400, CM = 900. Example: MCMXCIX = 1000+900+90+9 = 1999.
How do you convert a number to Roman numerals?
Break the number into thousands, hundreds, tens, and ones, then convert each part. Example: 2024 → 2000=MM, 0=nothing, 20=XX, 4=IV → MMXXIV. Example: 1999 → 1000=M, 900=CM, 90=XC, 9=IX → MCMXCIX. Example: 42 → 40=XL, 2=II → XLII.
What do the most common Roman numerals mean?
Frequently seen values: IV = 4, IX = 9, XIV = 14, XL = 40, XLII = 42, L = 50, XCIX = 99, C = 100, D = 500, M = 1000, MCM = 1900, MM = 2000, MMXXIV = 2024, MMXXV = 2025, MMXXVI = 2026.
What range of numbers can be converted?
The standard range is 1 to 3999 (I to MMMCMXCIX). Numbers 4000 and above would require a vinculum (overline) notation not in standard use. Most real-world uses — dates, chapter numbers, copyright years, Super Bowl editions — fall well within 1–3999.
What are the subtractive notation rules?
Only six subtractive combinations are valid in standard Roman numerals: IV (4), IX (9), XL (40), XC (90), CD (400), CM (900). Invalid forms like IC, IM, VX, LC are non-standard. A numeral can be repeated up to three times (III, XXX, CCC, MMM) but not four — use the subtractive form instead (4 = IV, not IIII).
Where are Roman numerals used today?
Common modern uses: movie copyright years (MMXXV = 2025 in film credits), Super Bowl editions (Super Bowl LVIII = 58), book chapters and outlines, royal names (Charles III, Henry VIII), clock faces (I–XII), Olympic Games, historic building cornerstones, and legal document numbering.
How do you write years in Roman numerals?
Convert each digit place separately. 2000 = MM, 2024 = MMXXIV, 2025 = MMXXV, 1999 = MCMXCIX, 1900 = MCM, 1776 = MDCCLXXVI. For the current year: MMXXVI = 2026. Formula: start with M for each thousand, then follow the standard rules for hundreds (C/D/M), tens (X/L/C), and units (I/V/X).
What is XLII in Roman numerals?
XLII = 42. Breaking it down: XL = 40 (50−10) and II = 2, total = 42. Famous for being the answer to life, the universe, and everything in The Hitchhiker's Guide to the Galaxy. Also the jersey number of Jackie Robinson, the number of US presidents (as of 2024), and the Super Bowl edition number played in 2008 (Super Bowl XLII).
