Decimal to Roman Numeral
Convert number to roman quickly with this free online calculator. The page explains the conversion rule, gives practical examples and provides a quick reference table.
Convert number to roman using the conversion factor used by this tool.
How to use the Decimal to Roman Numeral
- Enter the number you want to convert.
- Confirm the source unit shown beside the input.
- Choose decimal precision if you need more or less detail.
- Read the converted result.
- Copy the result when you need to use it elsewhere.
How the conversion works
Convert number to roman using the conversion factor used by this tool.
For a simple fixed-factor conversion, the calculator multiplies the entered value by the stated factor. Temperature scales and certain specialized tools use their specific mathematical relationship instead.
Common number to roman conversions
| number | roman |
|---|---|
| 1 number | 1 roman |
| 2 number | 2 roman |
| 5 number | 5 roman |
| 10 number | 10 roman |
| 20 number | 20 roman |
| 50 number | 50 roman |
Example
For example, entering 1 number gives approximately 1 roman using the rule above. Change the input to test your own value.
Frequently asked questions
Accuracy note: This calculator is a practical reference. For regulated, safety-critical or specialized work, verify the result against the applicable standard.
Page reviewed: August 24, 2026.