Roman numeral converter for numbers from 1 to 3,999. Convert in either direction, review the steps, and copy the number or numeral.
A Roman numeral converter translates between Arabic numbers (the everyday 1, 2, 3 ...) and Roman numerals (I, II, III, IV, V, ...). Use it to read movie copyright dates (MMXXIV), Super Bowl numbering (LVIII), chapter headings (Chapter IV), monarch names (Elizabeth II), and watch dials.
This tool handles the full standard range, from 1 (I) to 3,999 (MMMCMXCIX): the range supported by this converter.
Type a number to see it as a Roman numeral, or type a Roman numeral (mixed case is fine) to see its Arabic value. Both directions work live: no submit button. Review input warnings for nonstandard forms such as IIII for 4 or VL for 45.
I: 1
V: 5
X: 10
L: 50
C: 100
D: 500
M: 1,000
These seven symbols combine to write every number from 1 to 3,999. Larger numbers require vinculum (overline) notation, which this converter does not cover.
1 = I 2 = II 3 = III 4 = IV 5 = V
6 = VI 7 = VII 8 = VIII 9 = IX 10 = X
40 = XL 50 = L 90 = XC 100 = C
400 = CD 500 = D 900 = CM 1000 = M
2026 = MMXXVI 2000 = MM 1999 = MCMXCIX
Bidirectional: number → Roman and Roman → number, in the same UI
Handles the full standard range, 1 to 3,999 (I to MMMCMXCIX)
Mixed-case input accepted (mcmxcix = MCMXCIX = 1999)
Validates Roman input: clearly flags invalid forms like IIII, VV, or IC
"Step-by-step" toggle shows how the conversion was built (useful for students)
One-click copy in either direction
Dark mode that follows your system preference
Type a number into the top field (e.g. 2026).
The Roman numeral appears live in the bottom field (e.g. MMXXVI).
Or type a Roman numeral into the bottom field: the Arabic value appears above.
Toggle Show steps to see the decomposition.
Click Copy on either field to copy the value.
Where Roman numerals still come up:
Movie & TV credits: copyright dates like MMXXIV are standard.
Super Bowl & Olympic numbering: Super Bowl LVIII, Tokyo XXXII Olympiad.
Watch & clock dials: verifying what number a Roman-numeral watch face is showing.
Book chapter & section numbering: "Chapter IV", "Volume III" in academic and legal texts.
Monarch & pope names: Elizabeth II, Louis XIV, Pope John Paul II.
Outline notation: the classic I. A. 1. a. structure for essay outlines.
Tattoos & jewellery: converting a birth year or anniversary date into Roman numerals for engraving.
School & math homework: teaching subtractive notation, place value, and number-system history.
Quiz & trivia preparation: quickly verifying answers to Roman-numeral questions.
The output uses subtractive notation correctly (IV not IIII, IX not VIIII, XL not XXXX, CM not DCCCC) per the modern convention. Check the output against these forms when reviewing a conversion.
Toggle "Show steps" to see how 1999 is built as M + CM + XC + IX. Read the parts separately to understand how the total is built.
IV instead of IIII?Modern Roman numerals use subtractive notation: when a smaller numeral precedes a larger one, you subtract. So IV = 5 − 1 = 4. Historically IIII was also used (and still appears on some traditional clock faces and watches like Rolex), but standard form is IV.
1999 = 1000 + 900 + 90 + 9 = M + CM + XC + IX = MCMXCIX. Each century, decade, and unit needs its own subtractive form. Read each part separately when a numeral looks long.
In standard form: 3,999 = MMMCMXCIX. Larger values need vinculum (overline) notation, where a bar over a numeral multiplies it by 1,000: but that notation isn't fully standardised, so this converter stops at 3,999.
You don't: the Roman system has no symbol for zero. The concept of zero arrived in Europe long after the Roman numeral system was established. Medieval mathematicians sometimes used N (from Latin nulla) as a placeholder, but it isn't a standard Roman numeral.
A horizontal bar drawn above a Roman numeral to multiply its value by 1,000. V̄ = 5,000, X̄ = 10,000, and so on. This converter focuses on the standard 1-3,999 range, so it does not output vinculum forms.
MMXXVI: that's MM (2000) + XX (20) + VI (6). Use the result for a year label or copyright line.
Yes. Lowercase forms (i, v, x, l, c, d, m) have the same meaning and are common in outline notation (e.g. sub-points i, ii, iii within an outline). Our converter accepts both cases.
How to Use Roman Numeral Converter - Numbers to Roman and Back
Enter a number from 1 to 3,999 to convert it to Roman numerals, or enter a Roman numeral to convert it back to a number.
Read the result and check any input warning. Use Show steps to inspect the parts of the conversion.
Use Copy beside the value you need. Check the numeral before using it in a date label, engraving, or document.
Roman numeral converter for numbers from 1 to 3,999. Convert in either direction, review the steps, and copy the number or numeral.
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Jun 10, 2026Type:
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