# Roman Numeral Converter

> Convert numbers to roman numerals and roman numerals back to numbers, from 1 to 3999.

To convert roman numerals, enter a number to get its roman form, or a roman numeral to get its value. The converter covers 1 to 3999 and validates subtractive notation, so it rejects malformed input like IIII or IC and suggests the correct form.

**URL:** https://convertto.tech/t/roman-numeral-converter
**Category:** Number Tools (https://convertto.tech/c/number-tools)
**Privacy:** Runs entirely in the browser; no upload
**Cost:** Free, no sign-up
**Last updated:** 2026-08-01

## Key facts

- **Privacy:** Runs entirely in your browser — nothing is uploaded
- **Cost:** Free, unlimited, no sign-up

## How to use

1. Enter or paste your value.
2. Choose the direction.
3. The result appears immediately — copy or download it.

## FAQ

### Why is 4 written IV and not IIII?

Standard roman numerals use subtractive notation: a smaller numeral before a larger one is subtracted. IIII appears on some clock faces but is not the standard form, and this converter rejects it.

### What is the largest roman numeral?

Using standard letters the maximum is 3999 (MMMCMXCIX). Larger values required a vinculum — an overline multiplying the numeral by 1000 — which has no standard plain-text representation.

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