Convert numbers to and from Roman numerals
Numbers above 3,999 use vinculum notation: a line above a numeral multiplies its value by 1,000.
So ICCCXXXIII = 1,000,333.
Did you know?
Why Movies Use Roman Numerals in Credits
Look at the end credits of almost any film and you'll see the year in Roman numerals: MMXXVI instead of 2026. This tradition started as a way to make the copyright year less obvious — studios didn't want audiences to know immediately how old a film was during reruns. The practice stuck, and now it's just how it's done.
Read more →Florence Banned Arabic Numerals
In 1299, the city of Florence banned Hindu-Arabic numerals. The reasoning? They were too easy to forge. A 0 could become a 6 or 9. A 1 could become a 7. With Roman numerals, altering a number required adding or removing entire letters. The new system was so efficient it was too efficient for a world without modern auditing.
Read more →Where do Roman numerals come from?
It is thought Roman numerals come from hand signals and tally marks. The stroke I represents a finger, the V represents the gap between thumb and fingers for five, and the X represents hands crossed for ten. The L, C, D, and M come from modifications of Greek letters like chi, theta, and phi to represent 50, 100, 500, and 1,000. Over time, these marks changed into the Latin letters people recognize today. There is no 0 in the Roman alphabet, as the concept for the number 0 didn't fully develop until India invented it around 600 CE / 10600 HE.