Roman Numeral Converter

How it works

Type one value per line; the result appears in the right box in the same order as you type. With the direction on automatic, each line's type is detected by itself: type 2026 and you get MMXXVI, type MCMLXXXIV and you get 1984. Lowercase input like xlix is accepted and converts to 49. The range is 1 to 3999, because standard Roman notation has no zero and no everyday symbol above 3999; out-of-range lines are flagged with the reason. Spelling is checked too: type the IIII you know from clock faces and the tool reads the value but tells you the standard form is IV; try a shortcut like IC and it shows that 99 is correctly written XCIX. Paste a whole list at once for jobs like checking homework, decoding the MMXXIV at the end of a film's credits, reading Super Bowl LVIII, or converting a birth date for a tattoo or engraving before it becomes permanent.

This tool is also known as roman numeral converter, roman numerals to numbers, 1984 in roman numerals, convert numbers to roman numerals, what year is mcmxciv.

What is Roman numerals?

Roman numerals write numbers with seven letters — I=1, V=5, X=10, L=50, C=100, D=500, M=1000. There is no place value: symbols are written side by side and added up, and a smaller symbol before a larger one is subtracted, so MMXXVI reads 1000+1000+10+10+5+1 = 2026. The same symbol repeats at most three times. Because the system is additive, long numbers get bulky and there is no zero at all — which is why it retired from calculation and lives on in ceremonial display: century numbers, book volumes, monarchs' names, film production years and sports editions.

What is Subtractive notation (IV, IX, XL, XC, CD, CM)?

Subtractive notation is the rule that prevents a fourth repeat of the same symbol: a smaller-valued symbol written immediately before a larger one is subtracted instead of added. Standard spelling allows exactly six pairs — IV (4), IX (9), XL (40), XC (90), CD (400), CM (900). I may only be subtracted from V and X, X only from L and C, C only from D and M; V, L and D are never subtracted. That limit blocks improvised shortcuts: IC for 99 and MXM for 1990 are both invalid — the correct forms are XCIX and MCMXC. This tool reads such forms but recommends the standard.

How do Roman numerals differ from the numbers we use today?

Today's number system is positional: a digit's value depends on where it stands (the three 2s in 222 mean two hundred, twenty and two) and zero is what makes that possible. The Roman system is additive: every symbol has a fixed value and a number is the sum of its symbols plus the six subtractive pairs. That is why arithmetic in Roman numerals is painful — column addition and long multiplication need place value — and why there is no practical symbol above 3999. Once positional numerals spread through Europe, Roman numerals stopped being a calculating tool; today they appear wherever a number needs to look formal rather than be computed with.

The subtractive trap: why is 4 written IV and not IIII?

In Roman numerals the same symbol repeats at most three times in a row; instead of a fourth repeat, the subtractive rule kicks in: a smaller symbol placed before a larger one is subtracted. So 4 is IV (5-1) rather than IIII, 9 is IX, 40 is XL, 90 is XC, 400 is CD and 900 is CM. Subtraction is only valid in those six pairs — shortening 99 to IC (100-1) breaks the rule, the correct form is XCIX; 1990 is MCMXC, never MXM.

This tool runs both checks at once: enter a non-standard form and it still reads the value, but the line shows the standard spelling. That matters most where the numeral is about to become permanent — a tattoo, an engraved ring, a cornerstone. The one famous exception is the clock face: many clocks show 4 as IIII by watchmaking tradition, which is a design custom, not a spelling rule.

Where you still meet Roman numerals, and which direction to pick

Roman numerals retired from arithmetic centuries ago; today they survive in ceremonial and typographic roles. Where you meet one tells you which direction you need.

• Film and TV credits — the production year (MMXXIV) → Roman to number
• Super Bowl and WrestleMania editions (LVIII) → Roman to number
• Book volumes, chapters and preface pages (Vol. III, page xii) → Roman to number
• Birth dates for tattoos, rings and invitations → number to Roman
• Monarchs and popes (Elizabeth II, Benedict XVI) → both directions come up
• Checking homework or a mixed list → automatic direction handles it in one pass

Frequently asked questions

How is 1984 written in Roman numerals?

MCMLXXXIV. The parts: M is one thousand, CM is nine hundred (1000-100), LXXX is eighty, IV is four. Just type the number in the left box; the tool does the splitting for you.

Why is IC not accepted as 99?

The subtractive rule only allows six pairs: IV, IX, XL, XC, CD and CM — I can only be subtracted from V and X. The correct form of 99 is XCIX (90 + 9). If you enter IC, the tool understands the value but suggests the standard spelling.

Why can't it convert zero or numbers above 3999?

The standard Roman system simply has no symbol for zero, and the overline notation used above 3999 (V̄ = 5000) does not render reliably in ordinary fonts. So the tool honestly limits itself to 1-3999 and flags anything outside it.

Are lowercase Roman numerals valid?

As input, yes: type xlix and you get 49. Books number their preface pages in lowercase (i, ii, iii) — it is the same system. Output is always uppercase.