Roman to Numbers

Convert Roman numeral strings into decimal numbers and review common symbol values.

Roman Numeral
Valid symbols: I V X L C D M
Number
Result will appear here
Quick Reference
I→1
V→5
X→10
L→50
C→100
D→500
M→1000
IV→4
IX→9
XL→40
XC→90
CD→400
CM→900

What does Roman to Numbers do?

Roman to Numbers converts Roman numerals into decimal numbers.

  • Primary use: Roman to Numbers converts Roman numerals into decimal numbers.
  • Key technical fact: Subtractive pairs such as IV, IX, XL, XC, CD, and CM represent values before larger symbols.
  • Practical check: Check accepted digits, ranges, signs, prefixes, and rounding before copying the converted value into code.
Topic Direct answer Source
Direct answer Roman to Numbers converts Roman numerals into decimal numbers. Browser JavaScript
Key fact Subtractive pairs such as IV, IX, XL, XC, CD, and CM represent values before larger symbols. Browser JavaScript
Processing model Runs locally in the browser; no production Node server receives the input. Browser JavaScript

Convert Roman numerals to decimal numbers

Roman Numerals to Numbers reads Roman numeral symbols and returns the matching decimal value. Use it for dates, outlines, book chapters, movie sequels, clock faces, and historical references.

Standard symbols are I, V, X, L, C, D, and M. Subtractive notation places a smaller value before a larger one, as in IV for 4 and CM for 900.

How to use

  1. Type or paste the Roman numeral into the input field.
  2. Review the decimal number result and the quick reference symbols.
  3. Copy the number, or clear the field before converting another Roman numeral.

What is Roman numeral conversion?

Roman numeral conversion adds symbol values from left to right, subtracting a symbol when it appears before a larger symbol. For canonical modern notation, review unusual sequences because not every arrangement of valid symbols is standard.

Input notes

Use Roman numeral letters only. Typical modern notation represents values from 1 to 3999; larger values require overlines or other conventions that plain text tools may not support.

Example

MMXXIV combines 2000, 20, and 4 to produce 2024:

--- Roman Input ---
MMXXIV

--- Number Output ---
2024

MCP integration

MCP (Model Context Protocol) lets AI agents and apps discover and run Coding.Tools utilities for repeatable conversions, formatting, hashing, and generation workflows.

MCP tool name: roman-numerals-to-numbers

MCP endpoint: https://coding.tools/mcp

Call tools/list first. Each tool entry includes inputSchema, outputSchema, and examples so an AI agent or client can build valid arguments without guessing.

For tools/call, read result.content[0].text for the display value and result.structuredContent for machine parsing. Tool-level failures return isError: true; protocol failures return a JSON-RPC error.

Example tools/call request:

curl -s https://coding.tools/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -H "MCP-Protocol-Version: 2025-06-18" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"roman-numerals-to-numbers","arguments":{"input":"MMXXVI"}}}'

Most text and data tools accept an input string plus optional options. Browser-only image tools are listed for discovery and return a web UI link when they need browser image APIs.