Roman Numeral Converter: Write a Number in Roman Numerals
MathEnter a whole number from 1 to 3,999 and the converter writes it as a Roman numeral, showing how it is built from thousands, hundreds, tens and ones. A chart of common Roman numerals sits below the result.
Step by step
MMXXVI = MM + XX + VI
- Split the number into thousands, hundreds, tens and ones, and write each digit with the symbols I, V, X, L, C, D and M.
- Joining the parts (MM + XX + VI) from largest to smallest gives MMXXVI.
- A digit of zero writes nothing, and I, X, C and M never appear more than three times in a row.
Once every entry is valid, you’ll see each step of the calculation here.
Formula
- I, V, X
- the symbols for 1, 5 and 10
- L, C
- the symbols for 50 and 100
- D, M
- the symbols for 500 and 1,000
- IV, IX, XL, XC, CD, CM
- the six subtractive pairs: 4, 9, 40, 90, 400 and 900
How it works
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. Letters written from largest to smallest are added, so VIII is 5 + 3 = 8. A smaller letter placed before a larger one is subtracted, so IV is 5 − 1 = 4 and IX is 10 − 1 = 9. Only I, X and C are ever subtracted, and only in six pairs: IV, IX, XL, XC, CD and CM.
To write a number, the converter handles one digit at a time, from the thousands down to the ones, and joins the pieces. For 2026 that is 2000 + 20 + 6, written MM, XX and VI, so MMXXVI. For 1994 it is 1000 + 900 + 90 + 4, written M, CM, XC and IV, so MCMXCIV. A digit of zero writes nothing. The pieces appear under the result separated by plus signs, such as M + CM + XC + IV for 1994.
Two limits keep the result unique. I, X, C and M repeat at most three times in a row (III is 3, CCC is 300, MMM is 3,000), and V, L and D never repeat, which is why 4 is IV and 40 is XL. The largest number the seven letters can write is therefore 3,999, which is MMMCMXCIX, and that is this converter’s limit. The Romans had no symbol for zero and no negative numbers or decimals. For fractions, use the fraction calculator.
The formula
The formula lines work like a dictionary: each decimal position (thousands, hundreds, tens, ones) has one way to write the digits 1 to 9, and the Roman numeral is the four parts joined from largest to smallest. Because every digit has only one standard spelling, the result is unique: 49 is XLIX and never IL, since I can only be subtracted from V and X.
The converter writes the standard form only. Some clock faces and old inscriptions show IIII for 4 instead of IV; that is a tradition, not the modern rule. Above 3,999, a bar over a letter multiplies it by 1,000 (an X with a bar over it is 10,000), but that notation is not part of the standard range and is not offered here.
Example
How do you write 1984 in Roman numerals?
- Split the number by place value: 1984 = 1000 + 900 + 80 + 4.
- Write each part with Roman symbols: M + CM + LXXX + IV. Here 900 is CM (1000 − 100), 80 is LXXX (50 + 10 + 10 + 10) and 4 is IV (5 − 1).
- Join the parts from largest to smallest to get MCMLXXXIV.
In Roman numerals this number is MCMLXXXIV, built from M + CM + LXXX + IV.
Load this example into the calculatorFrequently asked questions
What is the Roman numeral for 2026?
2026 is written MMXXVI: MM for 2000, XX for 20 and VI for 6. Neighboring years follow the same pattern, so 2025 is MMXXV and 2027 is MMXXVII. For any other year, enter it in the converter above.
How do I read Roman numbers?
Read from left to right and add the values, but subtract a letter that stands before a larger one. In MCMXCIV, M is 1000, CM is 900 (1000 − 100), XC is 90 (100 − 10) and IV is 4 (5 − 1), so the total is 1000 + 900 + 90 + 4 = 1994. Splitting a numeral into those groups is the fastest way to check it.
What is XL in Roman numerals?
XL is 40: the X (10) before the L (50) is subtracted, so XL is 50 − 10. Enter 40 in the converter to see it. The same pattern gives XC for 90 (100 − 10) and CD for 400 (500 − 100).
How do you make 10,000 in Roman numerals?
The standard system stops at 3,999, so this converter does too. For 10,000, Roman numerals put a bar (a vinculum) over a letter to multiply it by 1,000: an X with a bar over it is 10,000. With only the seven standard letters and no bar, the only way is ten Ms in a row (MMMMMMMMMM), which breaks the three-in-a-row rule of the standard form. (The ancient apostrophus notation had a separate sign for 10,000, but it is not part of the standard system.)
What symbols are used for Roman numerals?
Seven letters: I (1), V (5), X (10), L (50), C (100), D (500) and M (1,000). Every other number is built from them, using the six subtractive pairs IV, IX, XL, XC, CD and CM for 4, 9, 40, 90, 400 and 900.
Where are Roman numerals used today?
On clock faces, in outlines and numbered lists, for book prefaces and chapters, in the copyright years of older films, and after the names of monarchs, popes and people with the same name (Elizabeth II, John Smith III). The NFL numbers the Super Bowl this way too (Super Bowl LX is the 60th), with Super Bowl 50 in 2016 as the one exception, which used Arabic numerals.
How does the Roman numeral converter work?
You enter a whole number from 1 to 3,999. The converter splits it into thousands, hundreds, tens and ones, writes each digit from a fixed pattern of Roman symbols, joins the pieces and shows them under the result. It always writes the standard form, with no repeated V, L or D.
Is the Roman numeral converter free to use?
Yes. It is free, needs no sign-up and has no limit on how many numbers you convert.
Is my data safe with the Roman numeral converter?
Yes. The conversion runs in your browser, so the number you type is not sent anywhere, and the page never asks for a name, email address or account.
Can I use the Roman numeral converter on mobile?
Yes. The page works in any modern browser on phones, tablets and computers, and the number field opens the numeric keypad on most phones.
What are the Roman numerals from 1 to 100?
From 1 to 10: I, II, III, IV, V, VI, VII, VIII, IX, X. The tens use X, L and C in the same pattern: 10 is X, 20 is XX, 30 is three Xs in a row, 40 is XL, 50 is L, 60 is LX, 70 is LXX, 80 is LXXX, 90 is XC and 100 is C. Other numbers join a tens part and a ones part: 47 is XLVII and 99 is XCIX. The chart under the converter lists the most used ones.
How do I write a date in Roman numerals?
Convert the month, the day and the year one at a time and join them with dots or dashes, in the order you want. October 9, 2026 in month, day, year order is X.IX.MMXXVI. Enter 10, 9 and 2026 in the converter to get the three parts.
Why is 4 written IV and not IIII?
The modern rule allows at most three equal symbols in a row, so 4 is written as 5 − 1, IV, and 9 as IX. IIII is a tradition you can still see on many clock faces and old inscriptions, but it is not the standard form this converter writes.
Is there a Roman numeral for zero?
No. The Romans had no symbol for zero, and no negative numbers or decimals, so the converter starts at 1. A zero digit inside a number simply writes nothing: 2005 is MMV.