Roman Numerals Converter

Roman numerals, both ways, instantly. Type 14 and XIV appears; type XIV and 14 appears.

Type a number and the numeral appears. Type a numeral and the number appears. There is no convert button and no direction to choose — the two fields are the same fact seen from either side. It works as a Roman numeral converter in one direction and a generator in the other, and it decodes what you are looking at without being told which way round you meant.

IT EXPLAINS ITSELF
Every result is broken down by place value: MCMLXXXVII is M + CM + LXXX + VII, not a wall of nine letters. And when a numeral is wrong the app names the rule rather than simply refusing — IIII repeats a symbol four times, IL is not one of the six subtractions the notation allows, and 49 is XLIX.

IIII OR IV
Almost every clock face ever made prints IIII. It is not a Roman numeral, and it is not a mistake either: it is a dial convention older than the subtractive rule. The app shows both, labelled, rather than pretending the question does not exist.

PRACTICE THAT MARKS YOU
A practice quiz that sets questions in both directions and checks the answers, at four levels from ten to 3,999. Wrong answers show the right one. It is there to help you learn to read the Latin numerals rather than look them up for ever.

WHERE NUMERALS ACTUALLY TURN UP
Years on films and cornerstones, monument dates, chapter and volume numbers, clock dials — and the date somebody wants to translate into numerals for a tattoo. Type a year, read it back.

PAST 3,999
Standard notation stops at MMMCMXCIX. The vinculum puts a bar over a numeral to multiply it by a thousand, so 4,000 is IV barred; the older apostrophus form, the one carved on ancient Roman stone, writes 1,000 as CIƆ. Both, up to 3,999,999.

IN YOUR OWN DIGITS
The number field accepts Arabic-Indic, Persian, Devanagari, Bengali, Gurmukhi, Tamil, Telugu, Thai and fullwidth digits, not only ASCII ones — and the numeral field takes the precomposed Unicode numeral characters some keyboards produce.

NO ACCOUNT, NO INTERNET, NO ADVERTS
The app works fully offline and stores nothing about you; its only network request is a check for a newer version. A dead app costs nothing to keep alive, so this one stays up and stays free.

Converting numerals is free and always will be. The purchase is one payment for the practice mode, the dates reference and the two big-number notations — never a subscription.

Recent changes:
Type a number or a numeral and the other appears instantly — with the rule behind it. Offline, no account, no adverts.