Roman Numeral Converterv1.0.0

Convert any Arabic number between 1 and 3999 into its Roman numeral equivalent, or translate a Roman numeral back into a standard Arabic number. The converter supports two modes: Number mode for individual values and Date mode for converting calendar dates into Roman numeral notation. Auto-detection identifies whether your input is an Arabic number or a Roman numeral, so you do not need to specify the direction manually.

• Select Number mode to convert a single value. Type an Arabic number such as 2024 or a Roman numeral such as MCMXCIX into the Enter an Arabic number (1-3999) or Roman numeral field. The converter auto-detects the input type when the Auto-detect input type setting is enabled.
• Select Date mode to convert a full calendar date. Enter the date in MM/DD/YYYY, YYYY-MM-DD, or as a standalone four-digit year in the Enter a date field. Each component (month, day, year) converts independently into Roman numerals.
• Click the Convert button or wait for the automatic 500-millisecond debounce to trigger the conversion. Results appear in the Result section below the input.
• Enable Show step-by-step breakdown in Settings to see how each Arabic number decomposes into Roman numeral components. For example, 1994 breaks down as 1000 (M) + 900 (CM) + 90 (XC) + 4 (IV) = MCMXCIV.
• Roman numeral conversion follows standard subtractive notation rules. The values I (1), V (5), X (10), L (50), C (100), D (500), and M (1000) combine with subtractive pairs IV (4), IX (9), XL (40), XC (90), CD (400), and CM (900).
• Toggle Uppercase Roman numeral output in Settings to switch between uppercase (XIV) and lowercase (xiv) output.
• Click Reset to clear all fields, remove saved state, and restore default settings.
• All inputs and settings persist automatically in local storage, so returning to the page restores your previous session.

Roman numerals appear across many disciplines and everyday contexts. Converting between numeral systems helps with reading historical documents, formatting creative works, and verifying inscriptions on buildings or monuments.

• Education: Verify homework answers when studying Roman numeral systems. Enter any number from 1 to 3999 and check the breakdown to understand how subtractive notation works with pairs like IV and CM.
• History and Architecture: Decode dates inscribed on buildings, monuments, and cornerstones. Switch to Date mode, enter the year MDCCLXXVI, and confirm it reads as 1776.
• Publishing and Media: Format chapter numbers, volume numbers, and sequel titles using Roman numerals. Convert 14 to XIV for a chapter heading or verify that a film sequel numbered VII corresponds to the seventh installment.
• Legal Documents: Confirm outline numbering in contracts and briefs where sections use Roman numeral hierarchies. Enter the numeral from a section header and verify the correct ordinal position.
• Event Planning: Format anniversary years, Super Bowl numbers, and Olympic numbering in Roman numerals. Convert 58 to LVIII for a Super Bowl graphic or 25 to XXV for a silver anniversary invitation.
• Clock and Watch Design: Verify numeral placement on clock faces that use Roman numerals. Check that IV or IIII appears at the four position and that IX is correct for nine.
• Genealogy: Interpret dates on old family records, gravestones, and church registers written in Roman numerals. Date mode parses the full date and converts each component for verification.