Roman Numeral Converter
Quickly convert Arabic numbers to Roman and Roman to Arabic — completely free and without limitations.
Roman numeral converter facilitates conversion between the classic Roman system and the modern Arabic system. Our tool works instantly, supports numbers above 3999 and helps understand conversion rules. Whether you need help with learning, work or out of curiosity, this converter was created to make your task easier.
Convert Arabic numbers to Roman
Convert Roman numbers to Arabic
Popular Roman numeral conversions
Years
- 1999 MCMXCIX
- 2000 MM
- 2024 MMXXIV
Special numbers
- 4 IV
- 9 IX
- 40 XL
- 90 XC
Large numbers
- 3999 MMMCMXCIX
- 4000 MV̅
- 5000 V̅
Rules for writing and reading Roman numerals
Basic symbols
| Symbol | Value | Usage |
|---|---|---|
| I | 1 | Units (1-3) |
| V | 5 | Fives |
| X | 10 | Tens (10-30) |
| L | 50 | Fifties |
| C | 100 | Hundreds (100-300) |
| D | 500 | Five hundreds |
| M | 1000 | Thousands (1000-3000) |
Writing rules
- Symbols I, X, C, M can appear at most 3 times in a row.
- Symbols V, L, D can appear only once (do not repeat).
- When a smaller symbol is after a larger one, we add its value (e.g. VI = 5+1 = 6).
- When a smaller symbol is before a larger one, we subtract its value (e.g. IV = 5-1 = 4).
- Symbol I can only stand before V and X.
- Symbol X can only stand before L and C.
- Symbol C can only stand before D and M.
- Numbers are written from largest to smallest value, except for subtraction cases.
Conversion examples
14 (XIV)
= 10 + (5-1) = 10 + 4 = 14
1999 (MCMXCIX)
= 1000 + (1000-100) + (100-10) + (10-1) = 1000 + 900 + 90 + 9 = 1999
2024 (MMXXIV)
= 1000 + 1000 + 10 + 10 + (5-1) = 2000 + 20 + 4 = 2024
Numbers above 3999
Traditionally, the Roman system allows writing numbers up to 3999 (MMMCMXCIX). For larger values, the overline symbol (vinculum) is used, which means multiplication by 1000:
- V̅ = V × 1000 = 5000
- X̅ = X × 1000 = 10000
- L̅ = L × 1000 = 50000
- C̅ = C × 1000 = 100000
Our converter also supports large numbers using this convention.
Frequently asked questions about Roman numeral conversion
Why do we still use Roman numerals?
Although Arabic numerals are commonly used in everyday calculations, Roman numerals remain an important element of our culture. We use them on clock faces, in century designations, chapter numbering, as well as in names of rulers, popes and events. Their aesthetics and historical significance mean they still have their place in the modern world.
Do Roman numerals have zero?
No, in the classical Roman system there is no symbol for zero. This system was created for practical, commercial and administrative purposes, where zero was not needed. The concept of zero as a number was introduced to Europe much later, along with the Arabic system.
Are there different ways to write the same Roman numeral?
Historically, there were certain variants of Roman numeral notation, but today we use standard rules that ensure uniqueness. For example, we write 4 as IV (not IIII), and 9 as IX (not VIIII). Our converter uses modern, standard notation rules.
Related topics
History of Roman numerals
Learn the fascinating history of the origin and evolution of the Roman numeral system from antiquity to modern times.
Applications in the modern world
Find out where and how Roman numerals are used in the modern world - from clocks to architecture.
List of Roman numerals to 1000
Complete list of Roman numerals from 1 to 1000 with their Arabic equivalents.