Roman Numeral Converter

The calculator converts numbers from 1 to 3999 into Roman numerals and back. 2026 is MMXXVI. 14 is XIV. IIII is not accepted, because 4 is IV.

This is not a date generator and not a cipher. Binary is on bin, hex and dec.

Inputs

Result

Enter a number from 1 to 3999 or a Roman numeral. The result will appear here.

How it works

The calculator builds Roman numerals from M, D, C, L, X, V, and I. 2026 is MMXXVI. 14 is XIV. 3999 is MMMCMXCIX.

Subtractive notation: 4 is IV, 9 is IX, 40 is XL, 90 is XC, 400 is CD, 900 is CM.

The range is 1 to 3999. Zero and 4000 have no Roman numeral in this range.

The other way, the calculator accepts only the canonical form. IIII is not accepted, because 4 is IV.

This is not a calendar year beyond the number itself. 2026 is MMXXVI regardless of the month.

You may type lowercase letters. The calculator reads them as uppercase.

Formula

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

Range 1 to 3999. IIII is not 4 here.

How to use

  1. Choose number to Roman numerals.
  2. Enter 2026. The result is MMXXVI.
  3. Enter 14. The result is XIV.
  4. The other way, enter XIV. The result is 14.

2026 is MMXXVI

M is 1000, X is 10, V is 5, I is 1. Two thousand twenty-six is MMXXVI.

M
1000. In 2026 there are two M marks.
IV
4. IIII is not accepted.
3999
MMMCMXCIX. The upper limit on this page.

Examples

Example 1

  • Direction: number to Roman numerals
  • 2026

MMXXVI

How do you write 2026 in Roman numerals? MMXXVI.

Example 2

  • Direction: number to Roman numerals
  • 14

XIV

How do you write 14? XIV, because 10 + 4.

Example 3

  • Direction: Roman numerals to number
  • XIV

14

What is XIV? 14.

Related calculators

Bin, hex and dec

A different numeral system, not Roman.

Use calculator →

Random number generator

A random number, not a Roman mark.

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Decimal to fraction

A common fraction, not Roman numerals.

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Frequently asked questions

How do you write 2026 in Roman numerals?

MMXXVI. Two Ms, then XX and VI.

How do you write 14?

XIV. X is 10, IV is 4.

What is XIV?

14.

Is IIII accepted?

No. 4 is IV.

What is the range?

From 1 to 3999. Zero and 4000 have no Roman numeral in this range.

Do lowercase letters work?

Yes. xiv means the same as XIV.

Is this a calendar year?

No. 2026 is MMXXVI regardless of the month.

How do you write 3999?

MMMCMXCIX.

Is this a Caesar cipher?

No. The cipher is on a separate IT page.

Is 4 IV, or IIII?

On this page it is IV. The calculator does not accept IIII.

Sources

Roman numerals write numbers with I, V, X, L, C, D and M.

Page updated in 2026.