Roman Numeral Converter — Convert Numbers to and from Roman Numerals
Convert between Roman numerals and Arabic numbers instantly. Full conversion table from I to MMMCMXCIX (1–3999), with rules and common uses.
Roman numerals appear on clock faces, movie credits, Super Bowl logos, building cornerstones, book chapters, and outlines. Converting them requires knowing just seven symbols and two rules. The CalcHub Roman Numeral Converter handles conversions in both directions instantly.
The Seven Symbols
| Symbol | Value |
|---|---|
| I | 1 |
| V | 5 |
| X | 10 |
| L | 50 |
| C | 100 |
| D | 500 |
| M | 1,000 |
Conversion Table (1–100)
| # | Roman | # | Roman | # | Roman | # | Roman |
|---|---|---|---|---|---|---|---|
| 1 | I | 11 | XI | 30 | XXX | 70 | LXX |
| 2 | II | 12 | XII | 31 | XXXI | 80 | LXXX |
| 3 | III | 13 | XIII | 40 | XL | 90 | XC |
| 4 | IV | 14 | XIV | 44 | XLIV | 99 | XCIX |
| 5 | V | 15 | XV | 49 | XLIX | 100 | C |
| 6 | VI | 16 | XVI | 50 | L | 200 | CC |
| 7 | VII | 17 | XVII | 55 | LV | 400 | CD |
| 8 | VIII | 18 | XVIII | 60 | LX | 500 | D |
| 9 | IX | 19 | XIX | 66 | LXVI | 900 | CM |
| 10 | X | 20 | XX | 69 | LXIX | 1000 | M |
Common Years in Roman Numerals
| Year | Roman | Context |
|---|---|---|
| 1776 | MDCCLXXVI | US Declaration of Independence |
| 1900 | MCM | Turn of century |
| 1999 | MCMXCIX | End of millennium |
| 2000 | MM | New millennium |
| 2024 | MMXXIV | Recent year |
| 2025 | MMXXV | Recent year |
| 2026 | MMXXVI | Current year |
| 2030 | MMXXX | Near future |
| 2050 | MML | Mid-century |
| 2100 | MMC | Next century |
The Two Rules
Rule 1: Addition
When a smaller value appears AFTER a larger value, ADD them.- VI = 5 + 1 = 6
- XV = 10 + 5 = 15
- CLXVI = 100 + 50 + 10 + 5 + 1 = 166
Rule 2: Subtraction
When a smaller value appears BEFORE a larger value, SUBTRACT the smaller.- IV = 5 − 1 = 4
- IX = 10 − 1 = 9
- XL = 50 − 10 = 40
- XC = 100 − 10 = 90
- CD = 500 − 100 = 400
- CM = 1000 − 100 = 900
Step-by-Step Conversion
Arabic to Roman: Break into place values
Example: 2,749- 2,000 = MM
- 700 = DCC
- 40 = XL
- 9 = IX
- Result: MMDCCXLIX
Roman to Arabic: Process left to right
Example: MCMXLIV- M = 1,000
- CM = 900 (C before M = subtract)
- XL = 40 (X before L = subtract)
- IV = 4 (I before V = subtract)
- Result: 1,000 + 900 + 40 + 4 = 1,944
Where Roman Numerals Are Used Today
| Use | Example |
|---|---|
| Clocks and watches | IV or IIII for 4 o'clock |
| Movie/TV sequels | Rocky II, Star Wars Episode IV |
| Super Bowl | Super Bowl LVIII (58) |
| Building dates | Cornerstones showing construction year |
| Book chapters | Chapter IX |
| Outlines | I, II, III for main sections |
| Monarchs/Popes | King Charles III, Pope Benedict XVI |
| Music theory | I, IV, V chord progression |
| Copyright | © MMXXVI |
How to Use the Converter
- Open the CalcHub Roman Numeral Converter
- Enter either a number (1–3,999) or a Roman numeral
- See the instant conversion in both directions
Why can't Roman numerals go above 3,999?
Standard Roman numerals max out at MMMCMXCIX (3,999) because there's no single symbol for 5,000. For larger numbers, Romans used a bar (vinculum) over a numeral to multiply by 1,000: V̅ = 5,000, X̅ = 10,000. This notation is rarely used today.
Why do some clocks show IIII instead of IV?
Several theories: (1) symmetry — IIII balances with VIII on the opposite side; (2) distinguishing from VI at a glance; (3) tradition dating back to medieval clockmakers. Both IIII and IV are correct.
Is there a Roman numeral for zero?
No. The Roman numeral system has no symbol for zero. The concept of zero came from Indian mathematics (via Arabic scholars) and wasn't part of the Roman system. This is one reason Roman numerals were eventually replaced by Hindu-Arabic numerals for math.
Related Tools
- Number Base Converter — binary, hex, octal
- Percentage Calculator — number operations
- Scientific Calculator — advanced math