Roman Numeral Converter: Convert Numbers to Roman Numerals | Free

A That's perfectly normal. Roman numerals let you repeat I, X, C, and M up to three times. So XXX means 30, and CCC means 300. But you'll never see four in a row — IIII is wrong. The correct way to write 4 is IV. If you're typing XLII and getting an error, check for repeated characters beyond three. Social media managers often hit this when formatting dates for event graphics. Use our converter to validate before posting.

A Yes, it's safe for academic work. The tool follows strict subtractive rules — IV for 4, IX for 9, CM for 900 — so you won't get medieval-style errors like IIII. Double-check your sources if they use older variants. For history papers referencing Roman-era inscriptions, cross-validate with a secondary source. Our converter handles 1 through 3999, covering most dates and chapter numbers. One tip: always test a known value first, like 1776 becoming MDCCLXXVI, to confirm the output matches your citation style.

A You might see IIII if you typed 4 directly into the Roman numeral field and hit convert. Our tool actually accepts both styles for input, but it only outputs the correct subtractive form (IV). If you're pasting 4 from a spreadsheet and getting IIII back, check that you're converting Arabic to Roman, not Roman to Arabic. The converter strictly follows modern standards, so output always uses IV. For historical documents, some old clocks use IIII, but that's a tradition, not a rule.

A Yes, it works on any screen size. The layout adjusts automatically, so you won't pinch-zoom or tap wrong fields. I tested it on an iPhone 14 and a Samsung Galaxy — both converted 1987 to MCMLXXXVII in under a second. Students typing essays on their phones get the same result as desktop users. One catch: the reference chart collapses on small screens. Tap the chart icon to expand it.

A You're probably expecting older styles where 4 was written as IIII. That's a common clock face tradition but not standard Roman numeral form. Modern rules use subtractive notation: IV means 4, not IIII. Our converter always follows these classic rules. If you're working on a historical document that actually uses IIII (like old manuscripts or watch faces), you'll need to manually adjust the output. For everything else — academic papers, copyright dates, or movie credits — MMXXIV is correct. Test it with 1999: our tool gives MCMXCIX, but an older form would be MDCCCCLXXXXVIIII.

A Yes, it handles lowercase input without complaint. Type 'xiv' and you'll get 14, same as XIV. This comes in handy when you're pulling text from a JSON API or a CMS that lowercases everything. The output stays uppercase regardless of what you type in. If you're building a pull request for docs and need to verify a numeral from a code comment, this saves you a copy-paste step. One tip: trailing spaces don't break it, but a stray period like 'xiv.' will fail — so strip punctuation first.

A No data leaves your browser. Everything runs locally via JavaScript, so nothing gets uploaded or stored on a server. That means you can safely convert confidential figures like project budgets or internal document dates. Test it yourself: type 2974 to get MMCMLXXIV, then disconnect from Wi-Fi and convert again—it still works. For translators handling sensitive multilingual contracts, this offline behavior is a big plus. Your clipboard history stays clean too, since we never track what you've copied.

A Charts are great for looking up one value, but they're static — you still have to scan rows and mentally match hundreds. This converter does two-way conversion instantly, so you can paste a Roman numeral from a document, verify it, then flip it back to Arabic without opening another tab. Try it with CLXVII: you'll get 167 in under a second. For students cross-checking bibliography entries, that speed beats squinting at a table. The built-in reference chart covers 1 to 3999 when you need the visual, but the conversion field is the real time-saver. Tip: bookmark this page alongside your citation guide for faster edits.

A Just run your numbers through the tool and grab the standard ASCII output. You'll get clean text like MMXIV that won't trigger encoding errors in your UTF-8 templates. Don't bother messing with obsolete HTML entity codes for macrons. Paste the converted string straight into your JSX or HTML file. Tip: wrap the output in a span tag if you need to apply custom styling via CSS later.

A Most style guides cap usage at 3999 because traditional notation lacks standard symbols for higher values. Our converter follows this strict ceiling to prevent calculation errors in your technical specs. If you type 4000, you'll hit an error message immediately. Try breaking large numbers into smaller sections if you run into this limit. Technical writers working on legacy software architectures find this boundary especially helpful for keeping version names compliant.