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Roman Numeral Converter

Numbers to Roman numerals and back, from 1 to 3,999.

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Result

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About this calculator

Type a number from 1 to 3,999 to get its Roman numeral, or type a Roman numeral such as MCMXCIV to get the number. The converter works out which you meant and shows the working.

Worked examples

Real numbers, worked out by the same calculator. Press “Use these numbers” to try one above.

2026 to Roman

Roman numeral
MMXXVI
Number
2,026

2,026 is MMXXVI in Roman numerals.

Show the working
  1. M is 1,000, leaving 1,026.
  2. M is 1,000, leaving 26.
  3. X is 10, leaving 16.
  4. X is 10, leaving 6.
  5. V is 5, leaving 1.
  6. I is 1, leaving 0.

MCMXCIV to a number

Number
1,994
Roman numeral
MCMXCIV

MCMXCIV is 1,994.

Show the working
  1. Read left to right. A smaller letter before a bigger one is subtracted (IV is 5 − 1), otherwise letters are added.
  2. MCMXCIV adds up to 1,994.

49 to Roman

Roman numeral
XLIX
Number
49

49 is XLIX in Roman numerals.

Show the working
  1. XL is 40, leaving 9.
  2. IX is 9, leaving 0.

The seven letters

LetterValue
I1
V5
X10
L50
C100
D500
M1,000

How the rules work

Letters are written from largest to smallest and added together: XVI is 10 + 5 + 1 = 16. To avoid four of the same letter in a row, a smaller letter is placed before a larger one and subtracted: IV is 5 − 1 = 4, IX is 10 − 1 = 9, XL is 40, XC is 90, CD is 400 and CM is 900.

Only I, X and C can be subtracted, and only from the next two larger letters, so 99 is XCIX, not IC.

Why only up to 3,999?

The standard system has no symbol above M (1,000) and never repeats a letter more than three times, so the largest number it can write is MMMCMXCIX (3,999). Larger numbers historically used a bar over a letter to multiply it by 1,000, which this converter does not use.

Frequently asked questions

What is 2026 in Roman numerals?

2026 is MMXXVI: MM (2,000) + XX (20) + VI (6).

Why is 4 written IV and not IIII?

The standard form avoids four identical letters in a row by subtracting: 5 − 1. (Some clock faces do use IIII, but that is decoration, not the standard rule.)

Is there a Roman numeral for zero?

No. The Romans had no symbol for zero.

What happens if I type an invalid numeral like IIII or VX?

The converter says it isn't valid in the standard form, and explains the letters to use.

Formulas tested against hand-worked answers. Last reviewed 29 September 2026. These calculators do arithmetic only; they are not financial, tax or legal advice.