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 CMXCIXCMXCIXDCXCIX = 999,999,699.
Did you know?
The Longest Roman Numeral Under 4000
The longest Roman numeral for a number under 4,000 is 3,888: MMMDCCCLXXXVIII. That's 15 characters. It uses every additive symbol (M, D, C, L, X, V, I) and repeats each one the maximum allowed number of times. It's the Roman numeral equivalent of a tongue twister.
Read more →Intentional Friction
In a world optimized for speed, Roman numerals slow you down. And sometimes that's the point. A copyright year in MMXXVI makes you pause and decode. A memorial date in MCMXLV forces a moment of effort — and that effort is itself a form of respect. Roman numerals turn reading a number into a small act of attention.
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.