Number to Roman Numeral Converter
Convert integers to Roman numerals
Type a value above — result appears instantly
Number to Roman Numeral Converter
Type any whole number from 1 to 3,999,999 and get the numeral straight away, along with the subtractions that built it. Paste a comma-separated list to convert several at once, or copy the link to send someone the exact result.
1994 becomes MCMXCIV. Tap a piece to see why.
CM is 1000 − 100, so it adds 900.
How to convert a number to Roman numerals
Enter a number
Any whole number from 1 to 3,999,999. For a batch, separate them with commas, like 42, 1994, 2026.
Read the numeral
It updates as you type. Above 3,999 some letters get a bar over them, which means times 1,000.
Check the working
The steps panel lists each subtraction: what came off, which letters it wrote and what is left.
Copy it or send the link
Copy any single result, or use the share link so the same conversion opens on someone else's screen.
How the conversion works
The method is greedy: take the biggest value in a fixed table that still fits, write its letters, subtract, repeat. The table has 25 rows from 1,000,000 down to 1, and pairs like CM and IV are rows of their own, so no step needs a special case.
The loop
for (letters, value) in TABLE:while number >= value:result += lettersnumber -= valuereturn result| Subtract | Writes | Left | So far |
|---|---|---|---|
| 1994 − 1000 | M | 994 | M |
| 994 − 900 | CM | 94 | MCM |
| 94 − 90 | XC | 4 | MCMXC |
| 4 − 4 | IV | 0 | MCMXCIV |
| 1994 = MCMXCIV | |||
The six subtractive pairs
I can sit before V or X, X before L or C, and C before D or M. Nothing else subtracts, so 99 is XCIX and never IC.
IV
4
5 − 1
not
IIIIIX
9
10 − 1
not
VIIIIXL
40
50 − 10
not
XXXXXC
90
100 − 10
not
LXXXXCD
400
500 − 100
not
CCCCCM
900
1000 − 100
not
DCCCC
Seven letters, and a bar for the big numbers
Everything is built from these seven letters. A bar drawn over a letter multiplies it by 1,000, which is how numerals past 3,999 get written. You will mostly meet the bar in old legal records and formal inscriptions.
Smallest to largest, one way to remember them:
I Value Xylophones Like Cows Dig Milk
- I1A single stroke, the oldest tally mark.
- V5Often explained as an open hand.
- X10Commonly read as two Vs meeting at the point.
- L50Thought to be half of an older sign for 100.
- C100From centum, Latin for hundred.
- D500Thought to be half of an old sign for 1,000.
- M1,000From mille, Latin for thousand.
With a bar on top
V
5,000
X
10,000
C
100,000
M
1,000,000
A few conversions worth seeing
4 in Roman numerals
IV
Not IIII. The Romans wrote both, but IV is the form used today. Clock faces are the exception.
42 in Roman numerals
XLII
XL is 40 and II is 2.
1994 in Roman numerals
MCMXCIV
Three subtractive pairs back to back, which is why it trips people up.
2026 in Roman numerals
MMXXVI
MM is 2000, XX is 20, VI is 6. Pure addition, no subtraction at all.
3888 in Roman numerals
MMMDCCCLXXXVIII
Fifteen letters, the longest numeral you can write without a bar.
5000 in Roman numerals
V
One letter with a bar over it. The bar multiplies by 1,000.
Questions people ask
Limits, the subtractive rules, batch mode and that clock oddity.
Take the biggest value from the list (1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1) that still fits, write its letters, subtract it and repeat with what is left. For 1994 that gives M, then CM, then XC, then IV: MCMXCIV. The converter shows each of those steps.
