How to use the converter
- Type a whole number from 1 to 3,999 in the Number box. The Roman numeral box fills in as you type.
- Or type letters (I, V, X, L, C, D, M) in the Roman numeral box to see the number. Lowercase works too.
- Read the two lines under the boxes. The first splits the value by place (thousands, hundreds, tens, ones); the second shows the letters for each place.
- Use Quick conversions for the current year and other common numbers.
The rules behind the conversion
Roman numerals use seven letters: I is 1, V is 5, X is 10, L is 50, C is 100, D is 500 and M is 1,000. You write them from largest to smallest and add the values. A smaller letter placed directly before a larger one is subtracted instead, and only six pairs are standard: IV (4), IX (9), XL (40), XC (90), CD (400) and CM (900). A letter never repeats more than three times in a row.
The converter works one place at a time. It splits the number into thousands, hundreds, tens and ones, then writes each digit with the pattern for that place: 1 is I, 2 is II, 3 is III, 4 is IV, 5 is V, 6 is VI, 7 is VII, 8 is VIII, 9 is IX, with X, L and C standing in for tens and C, D and M for hundreds. Reading a numeral runs the same table backward, and it accepts only the standard shape, so IIII, IC or VX are flagged instead of guessed.
Worked example: 2026
With the default input 2026, the tool shows two lines:
2026 = 2000 + 20 + 6
MM + XX + VI = MMXXVI
2000 is two thousands (MM), 20 is two tens (XX) and 6 is VI. Joined together they make MMXXVI. Typing MMXXVI in the Roman numeral box returns 2026.
Limits and edge cases
- Range. Standard numerals run from I (1) to MMMCMXCIX (3,999). Zero, negative numbers, decimals and anything above 3,999 get a plain-language message instead of a result.
- Non-standard spellings. If you type IIII, IL or a similar form, the tool tells you what it equals when read loosely and how that value is normally written (IIII reads as 4, written IV).
- Years. Convert each place in turn: 1999 is M + CM + XC + IX, which gives MCMXCIX. The year table above covers 1990 to 2035.
- Typing tips. Commas and spaces in the Number box are ignored, so 2,026 works. Letters in the Roman numeral box are capitalized for you.
Need another number system? The number base converter handles binary, octal and hexadecimal, and the decimal to fraction converter turns decimals into fractions.
Frequently asked questions
What is 2026 in Roman numerals?
2026 is MMXXVI: MM is 2000, XX is 20 and VI is 6.
Why is there no zero in Roman numerals?
Roman numerals were designed to record counts of things, and the Romans had no symbol for zero. Medieval scribes occasionally wrote the Latin word nulla (none) in tables, but no Roman numeral for zero exists, so 0 cannot be converted.
Why do some clocks show IIII instead of IV?
Clockmakers have long used IIII for 4, often explained as a way to balance VIII on the opposite side of the dial. Both forms appear on historic inscriptions, but IV is the standard modern form and the one this converter writes.
What is the largest number I can write in Roman numerals?
With the seven standard letters the largest is MMMCMXCIX, which is 3,999. Larger numbers traditionally put a bar over a letter to multiply it by 1,000, so a barred V is 5,000, but that notation is not part of the standard form this converter uses.
Sources: Encyclopaedia Britannica, Roman numeral; Wikipedia, Roman numerals.