Why is 4 written IV and not IIII?

The subtractive principle is used to avoid four consecutive identical symbols. Placing a smaller value before a larger one means subtraction: IV = 5 - 1 = 4. This rule applies to I before V and X, X before L and C, and C before D and M. Note that some clock faces still use IIII for aesthetic balance — that is an accepted stylistic exception, not the standard.

What is the largest Roman numeral this tool supports?

With vinculum notation (overlines) enabled, this tool converts up to 3,999,999. Without vinculum, the maximum is 3,999 (MMMCMXCIX). In classical Roman numeral usage the practical limit was around 3,999, but the vinculum convention extended the system by multiplying overlined symbols by 1,000.

Is there a Roman numeral for zero?

No. The Roman numeral system has no symbol for zero. The Latin word "nulla" (meaning "none") was used in its place. Zero as a numeric concept with its own symbol was developed independently in India and later introduced to Europe through Arabic mathematics — which is why our standard digits are called Arabic numerals.

Why do some clocks use IIII instead of IV for 4?

Several reasons have been proposed: visual symmetry on the clock face (IIII mirrors VIII on the opposite side), the historical preference of certain royal patrons, easier reading at a glance, and simpler manufacturing of clock dies. Either form is considered acceptable on clock faces, though IV is the standard in all other contexts.

How do I write a date in Roman numerals?

Convert the month, day and year separately and join them with dots or dashes. July 4, 1776 is VII.IV.MDCCLXXVI in US order, or IV.VII.MDCCLXXVI with the day first.

What are the 7 Roman numeral letters?

I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1,000. Every standard Roman numeral is built from these seven letters.

Roman Numeral Converter

Enter an Arabic number (1–3,999,999) to get its Roman numeral, or type a Roman numeral to convert it back. Enable vinculum mode for numbers above 3,999.

Type a number to get the Roman numeral, or type a Roman numeral to get the number.

Number to Roman

1 – 3,999,999

Arabic number

Use vinculum notation (overlines for 4,000+)

Quick:

Enter a number above to see its Roman numeral.

Roman to Number

Case-insensitive

Roman numeral

Enter a Roman numeral above to convert it.

Character highlighting:

M Valid symbol ? Invalid character

Standard symbols and their values. The subtractive combinations below are used to avoid four consecutive identical symbols.

Basic Symbols

Symbol	Value
M	1,000
D	500
C	100
L	50
X	10
V	5
I	1

Subtractive Combinations

Symbol	Value
CM	900
CD	400
XC	90
XL	40
IX	9
IV	4

Vinculum (overline) Symbols

Symbol	Value
M	1,000,000
D	500,000
C	100,000
L	50,000
X	10,000
V	5,000

Quick answer

Type a number to get the Roman numeral, or type a Roman numeral to get the number. 2026 is MMXXVI, 1999 is MCMXCIX and 3,999 (MMMCMXCIX) is the largest value in standard form. Turn on vinculum notation for numbers up to 3,999,999, where a bar over a letter multiplies it by 1,000.

Examples

Number	Roman numeral
4	IV
9	IX
14	XIV
40	XL
90	XC
400	CD
1999	MCMXCIX
2026	MMXXVI
3999	MMMCMXCIX

Enter a number or a Roman numeral.

Summary

Enter an Arabic number (1–3,999,999) to get its Roman numeral, or type a Roman numeral to convert it back. Enable vinculum mode for numbers above 3,999.

How it works

To convert a number to Roman numerals: type any integer from 1 to 3,999,999 in the top input field.
Toggle "Use vinculum notation" to enable overlines for thousands (required for values above 3,999).
To convert Roman numerals back to a number: type or paste the Roman numeral string in the lower input field.
Use the preset year buttons (2024, 1969, 1776) to test common conversions instantly.
Expand the reference table at the bottom to review all Roman numeral symbols and their values.

Use cases

Decoding old documents, inscriptions, and monuments that use Roman numerals for dates or chapter numbers.
Naming children, pets, or creative works with stylized Roman numeral versions of birth years.
Tattoo design: verify the exact Roman form of a significant number before committing to ink.

Frequently Asked Questions

Last updated: 2026-05-28 · Reviewed by Nham Vu