Roman Numerals Converter

Convert numbers to Roman numerals and back, with step-by-step breakdown.

Quick:
Roman Numeral Reference
1 I
4 IV
5 V
9 IX
10 X
40 XL
50 L
90 XC
100 C
400 CD
500 D
900 CM
1,000 M
2,024 MMXXIV
2,025 MMXXV
2,026 MMXXVI
Key Rules
  • Symbols are generally written largest to smallest, left to right
  • Subtractive notation: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900
  • I, X, C, M can be repeated up to 3 times in a row
  • V, L, D are never repeated
  • Standard Roman numerals cover 1–3,999 (MMMCMXCIX)

Frequently Asked Questions

What are the basic Roman numeral symbols and values?

The seven symbols: I=1, V=5, X=10, L=50, C=100, D=500, M=1000. Numbers are formed by combining symbols. Subtractive notation handles 4s and 9s: IV=4, IX=9, XL=40, XC=90, CD=400, CM=900. Rules: never repeat a symbol more than 3 times; only one subtraction per symbol.

What is 2025 in Roman numerals?

2025 = MMXXV. Breaking it down: MM = 2000, XX = 20, V = 5. Common year conversions: 2024 = MMXXIV, 2025 = MMXXV, 2026 = MMXXVI, 2030 = MMXXX, 1999 = MCMXCIX.

How do you write numbers larger than 3,999 in Roman numerals?

Numbers above 3,999 traditionally use vinculum notation — a horizontal bar (overline) above a symbol multiplies its value by 1,000. V̄ = 5,000; X̄ = 10,000; L̄ = 50,000; C̄ = 100,000; D̄ = 500,000; M̄ = 1,000,000. This calculator supports vinculum notation up to 3,999,999.

Where are Roman numerals still used today?

Roman numerals appear in: clock and watch faces, book chapter numbers, film and TV sequel numbering (Rocky II, Super Bowl LIX), building cornerstones, royal and papal names (King Charles III), academic outlines, and movie copyright dates. They convey a sense of tradition and formality.