Roman Numeral Converter
Convert numbers to Roman numerals and back, from 1 to 3,999. Perfect for dates, titles and historical references.
Roman numeral
MCMXCIV
Last updated: February 2026
How this calculator is verified
Checked by True Calculator automated test suite on
- Formula verified against a published worked example in the automated test suite
- Edge cases (zero, negative, boundary and unit-mismatch inputs) covered by unit tests
The full verification method is on our how we verify page. Found an error? Tell us and we will re-check it.
When to Use This Calculator
Roman numerals may be ancient, but they still appear all around Indian life, and this converter handles them instantly. Students encounter them in history chapters, exam papers and the dates on school certificates, so the tool helps decode years like MDCXXXII for 1632. Film buffs use it for movie release years in titles, and sports fans read event numbers written in Roman style. Clock faces with Roman numerals are common in offices and homes, and the converter helps read the time at a glance. Publishers use Roman numerals for book chapters and front-matter page numbers, so editors and authors convert section numbers quickly. The converter supports the full range from 1 to 3,999, uses standard subtractive forms such as MCMXCIV for 1994, and validates input strictly, so invalid or non-standard numerals like MMMM are rejected rather than silently misread.
How to Use This Calculator
- Step 1: Choose the direction: number to Roman, or Roman to number.
- Step 2: For number to Roman, enter any whole number from 1 to 3,999.
- Step 3: For Roman to number, type the numeral using letters I, V, X, L, C, D and M.
- Step 4: Read the converted value, with invalid or out-of-range inputs clearly flagged.
Worked Example
A history student in Kolkata is preparing a project on the Taj Mahal, built in 1632. She enters 1632 and the converter returns MDCXXXII. Her teacher then asks the class to decode the year 1994 from a film title, and the converter turns MCMXCIV back into 1994. A classmate experiments with 58, which becomes LVIII, and checks the Roman numeral for 3,999, the maximum supported value, which is MMMCMXCIX. The student also learns that entering 4,000 is rejected, because traditional Roman numerals only reach 3,999 without special overline notation.
Tips and Common Mistakes
- •Tip 1: Remember the subtractive pairs: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400 and CM = 900.
- •Tip 2: A smaller letter before a larger one subtracts, and after it adds, so VI = 6 but IV = 4.
- •Tip 3: The converter accepts lowercase input, so typing "xiv" works the same as "XIV" and gives 14.
- ✗Mistake 1: Writing invalid forms like IC for 99, which is not standard; the correct form is XCIX.
- ✗Mistake 2: Entering zero, which does not exist in Roman numerals, or numbers above 3,999 that need overline notation.
Frequently Asked Questions
How do Roman numerals work?
Roman numerals use seven letters: I (1), V (5), X (10), L (50), C (100), D (500) and M (1,000). Smaller values before larger ones subtract, like IV = 4, and after them they add, like VI = 6.
What is the largest number I can convert?
The calculator supports 1 to 3,999. Roman numerals beyond 3,999 traditionally use bars over letters, which are not supported here.
Why is 1994 written as MCMXCIV and not MCDLXXXXIIII?
Standard Roman numerals use subtractive forms to keep numbers short: CM = 900, XC = 90 and IV = 4. This compact style is the one used in clocks and classic inscriptions.
Can I convert lowercase Roman numerals?
Yes. The converter accepts lowercase input like "xiv" and treats it the same as "XIV", which both equal 14.
Where are Roman numerals still used today?
They appear on clock faces, movie release years, book chapters, Super Bowl titles, building cornerstones, and many Indian school examination papers.
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