Roman Numeral Converter
Please provide a number or Roman numeral below to convert to the other format.
Roman Numeral Date Converter
Please provide a date in numeric or Roman numeral form below to convert to the other format. It accepts -, ., \, /, |, or space as separators. You can use common formats like MM/DD/YYYY, DD/MM/YYYY, or YYYY/MM/DD.
About Roman Numerals
A Roman numeral is a system for expressing numbers that originated in the Roman Empire. It is still used in certain cases today, such as on clocks or watch faces, book chapters, and for numbering large events such as the Olympics and the Superbowl.
Basic Roman Numerals
| Roman numerals | I | V | X | L | C | D | M |
|---|---|---|---|---|---|---|---|
| Arabic numbers | 1 | 5 | 10 | 50 | 100 | 500 | 1,000 |
Rules for Reading and Writing Roman Numerals
- Consecutive numerals are added when they are equal or the left numeral is larger (e.g., VI = 6, MCL = 1150).
- When a smaller numeral precedes a larger one, it is subtracted (e.g., IV = 4, CM = 900).
- V, L, and D are never repeated and cannot be used before larger symbols.
- Numerals can be repeated up to 3 times (e.g., III, XXX).
- I can only be subtracted from V or X. X can only be subtracted from L, C, or M.
Large Numbers with Vinculum
A vinculum (overline) multiplies the value by 1,000. In this converter, use an underscore (_) before a numeral to indicate a vinculum.
| Roman numerals | _I | _V | _X | _L | _C | _D | _M |
|---|---|---|---|---|---|---|---|
| Arabic numbers | 1,000 | 5,000 | 10,000 | 50,000 | 100,000 | 500,000 | 1,000,000 |