plainlyRoman numerals
to numbers
Read the letters. Reveal the number.
Convert either way, with every part explained.
Number
2,026
MMXXVI = 2,026
How it adds up
M (1,000) + M (1,000) + X (10) + X (10) + V (5) + I (1) = 2,026
Each symbol in this numeral is added; no subtractive pair is needed.
Copies the plain number without comma grouping, or the uppercase Roman numeral.
Standard notation for 1–3,999. Updates as you type. Your input stays in this tab.
Seven letters.
Thousands of numbers.
This converter turns Roman numerals to numbers and works in reverse on the same page. Enter letters such as CDXLIV, or switch direction and enter 444. The result explains the value of each symbol or subtractive pair, so you can check the conversion as well as copy it.
Roman numeral values
- I
- 1
- V
- 5
- X
- 10
- L
- 50
- C
- 100
- D
- 500
- M
- 1000
For modern writing conventions, see the Government of Canada’s Roman numeral reference. This tool uses standard subtractive notation within the range 1–3,999.
Read a subtractive pair together
The six supported pairs are IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, and CM = 900. In each, the smaller first symbol is subtracted from the larger one. Other symbol values are added. For example, CDXLIV = 400 + 40 + 4 = 444.
Order and repetition matter
Modern forms group the thousands, hundreds, tens, and ones in that order. A symbol cannot simply be placed anywhere to make a desired total. IC is not the standard form of 99; XCIX is. Repeated V, L, or D and more than three consecutive I, X, or C are rejected.
A conversion
you can check.
Example: decode MCMLXXXIV
Start with M = 1,000. The pair CM contributes 900; L contributes 50; XXX contributes 30; IV contributes 4. The total is 1,984. The result breakdown keeps the subtractive pairs intact rather than treating them as unrelated characters.
Example: write 2,047 in Roman numerals
Split it into 2,000 + 40 + 7. Two Ms represent 2,000; XL represents 40; VII represents 7. Put them together to obtain MMXLVII. In the number field, enter 2047 without a comma.
| Roman numeral | Number |
|---|---|
| IV | 4 |
| XII | 12 |
| XLIX | 49 |
| XCIX | 99 |
| CDXLIV | 444 |
| MCMLXXXIV | 1,984 |
| MMXXVI | 2,026 |
| MMMCMXCIX | 3,999 |
What this converter accepts
Uppercase and lowercase Latin letters work, and Unicode Roman numeral characters such as Ⅻ are normalized to their letter equivalent, XII. Spaces around the input are ignored; spaces inside a numeral are not. Number inputs must be whole numbers between 1 and 3,999. Fractions, negative values, and zero are outside this converter’s range.
Historical forms and larger values
Some clocks use IIII for four. Historical notation also includes other variants and overlines for larger values. This tool deliberately supports the modern I–MMMCMXCIX range rather than guessing how a historical inscription should be interpreted.
Letters in.
An answer out.
How do I convert Roman numerals to numbers?
Choose Roman numerals → numbers and enter your numeral. The converter checks standard notation, adds ordinary symbol values and subtractive-pair values, then shows the whole-number result and a breakdown.
Can I convert numbers to Roman numerals?
Yes. Switch the direction and enter a whole number from 1 to 3,999. The current valid result carries over when you switch, making it easy to check the reverse conversion.
Why does IC not work for 99?
IC is not an allowed subtractive pair in modern standard notation. Write 99 as XCIX: XC is 90 and IX is 9.
Can I enter lowercase Roman numerals?
Yes. For example, xliv converts to 44. The result shows the normalized uppercase form, XLIV.
Why is IIII rejected when it appears on clocks?
IIII is an established clock-face variant, but this converter validates standard subtractive notation, where four is IV. It does not claim that every historical variant is incorrect.
What is the largest supported number?
3,999, written MMMCMXCIX. Larger values need conventions outside this converter’s supported range, such as overlines. The tool does not interpret those marks.
What exactly does Copy result copy?
It copies the number without grouping commas, such as 2026, or the uppercase Roman numeral, such as MMXXVI. The explanation stays on the page.
More ways to work with numbers.
Significant figures calculator Acronym generatorAll tools