🏛️ Classical Mathematics & Numerals
Two-Way Roman Numeral Converter
Convert standard Arabic numbers (1–3,999) to Roman numerals and Roman numerals to numbers with step-by-step notation.
Historical Presets:
Current Year (2026 = MMXXVI)
Orwell's 1984 (MCMLXXXIV)
US Independence (1776 = MDCCLXXVI)
999 (CMXCIX)
The Answer (42 = XLII)
Conversion Result
MMXXVI
Roman Numeral Symbols & Subtractive Rules
Roman numerals originate from the ancient Roman numerical system based on seven fundamental capital letter symbols:
| Symbol | Value | Origin Description |
|---|---|---|
| I | 1 | A single notch tally mark. |
| V | 5 | Open palm hand shape (five fingers). |
| X | 10 | Two crossed tally lines. |
| L | 50 | Evolved from the Chalcidian Greek letter Psi. |
| C | 100 | Abbreviation of Latin Centum (hundred). |
| D | 500 | Half of the Greek Phi numeral symbol. |
| M | 1,000 | Abbreviation of Latin Mille (thousand). |
Standard Subtractive Notation Rules
To avoid writing four identical consecutive symbols (e.g. IIII or CCCC), standard subtractive notation is used:
Iplaced beforeV(5) orX(10) indicates one less:IV= 4,IX= 9.Xplaced beforeL(50) orC(100) indicates ten less:XL= 40,XC= 90.Cplaced beforeD(500) orM(1000) indicates one hundred less:CD= 400,CM= 900.