Roman Numeral Converter
Runs locally in your browser. Nothing leaves your device.Convert decimal numbers from 1 to 3999 and modern canonical Roman numerals bidirectionally in your browser.
Input
Private by design: your values never leave your device.
Output
Decimal value
2026
Roman uppercase
MMXXVI
Roman lowercase
mmxxvi
Canonical
yes
Breakdown and explanation
Tokens
M + M + X + X + V + I
Values
1000 + 1000 + 10 + 10 + 5 + 1
Place values
2000 + 20 + 6
Symbol statistics
M:2 · X:2 · V:1 · I:1
Symbol table and rules
C = 100
D = 500
I = 1
L = 50
M = 1000
V = 5
X = 10
How it works
- 1
Enter a decimal or Roman numeral
Enter a decimal number from 1 to 3999 or a Roman numeral.
- 2
View the result and breakdown
See the converted result along with the explanation of the breakdown and place values.
- 3
Copy the result
Copy the value in uppercase or lowercase.
Good to know
The Roman numeral converter converts bidirectionally between decimal numbers and Roman numerals in the range 1 to 3999, directly in your browser. Input is checked against modern canonical rules — for non-canonical notation, the tool suggests the correct modern form.
Calculation runs locally in the browser. Modern canonical notation differs from historical variants; negative numbers, zero, and overline notation for very large numbers are not supported.
Typical use cases
Convert year numbers for engravings or titles
Convert a year such as 2026 into Roman numerals, for example for engravings, film titles, or monument inscriptions.
Decode Roman numerals from texts
Convert Roman numerals from historical texts, chapter numbering, or clocks into decimal numbers.
Tips for better results
Let non-canonical notation be corrected
For non-modern-canonical input, the tool suggests the correct form, which you can apply directly.
Note the 1 to 3999 range limit
The tool only supports values from 1 to 3999, since modern canonical Roman notation has no unambiguous standard representation for larger numbers.
Features
Bidirectional conversion
Convert from decimal to Roman numeral and back.
Local conversion
Calculation happens directly in the browser, without transmission to a server.
Breakdown and symbol statistics
See the breakdown into place values and a statistic of the symbols used.
Frequently asked questions
What number range is supported?
1 to 3999. Negative numbers, zero, and overline notation for larger numbers are not supported.
Are my inputs uploaded?
No. Conversion runs entirely locally in the browser.
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