Roman Numeral Converter

Convert standard Roman numerals to Arabic numbers or integers from 1 to 3999 to Roman numerals

Your result will appear here.

About the Roman Numeral Converter

Roman Numeral Converter translates between ordinary integers and the standard modern Roman numeral notation built from I, V, X, L, C, D and M. It is useful for dates, chapter numbers, clocks and historical-style labels.

Roman numerals are not a positional base system like decimal. Standard modern notation uses subtractive pairs such as IV for 4 and IX for 9, with conventions limiting repetition and ordering.

How to Use the Roman Numeral Converter

  1. Enter a positive integer or Roman numeral.
  2. Choose the conversion direction.
  3. Calculate the standard Roman representation or integer value.
  4. Check that Roman input follows supported canonical rules rather than arbitrary letter ordering.

How the Calculation Works

Integer-to-Roman conversion repeatedly subtracts the largest valid numeral values, including subtractive pairs such as CM=900, XC=90 and IV=4.

Roman-to-integer conversion scans symbols and treats a smaller value before a larger value as subtraction under valid pairs; otherwise values are added.

Worked example

Roman Numeral Converter Worked Example

1994 to Roman numerals

1994 = 1000 + 900 + 90 + 4 = M + CM + XC + IV = MCMXCIV.

Result guide

Understanding Your Roman Numeral Converter Result

The result follows a standardized modern convention. Historical inscriptions sometimes used alternative forms, so authentic ancient usage can differ from the canonical output. Standard Roman notation also avoids invalid repetitions such as VVV or subtractive forms like IL for 49. The canonical modern form for 49 is XLIX, using XL for 40 and IX for 9. The converter should reject or normalize non-standard input instead of silently treating every letter sequence as valid.

Before you rely on the answer

Assumptions and Limitations

  • Input integer lies within the converter’s supported range.
  • Roman input uses recognized symbols.
  • Decimals and ordinary fractions are not silently rounded into Roman integers.

Practical tip

Using This Result in Practice

For formal output, prefer the canonical compact form instead of repeated additive alternatives such as IIII when IV is the standard representation expected by the calculator.

Common questions

Roman Numeral Converter FAQ

What is 4 in Roman numerals?

IV.

What is 900 in Roman numerals?

CM.

Can Roman numerals represent decimals directly?

The standard modern integer notation used by this converter does not represent ordinary decimal fractions.