Roman Numeral Converter
Convert integers 1–3999 and canonical modern Roman numerals with a symbol-group breakdown.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Encode by descending Roman numeral groups; decode only if the input re-encodes to the same canonical form.
M=1000, D=500, C=100, L=50, X=10, V=5, I=1; subtractive pairs IV IX XL XC CD CM
Worked example
2026 is MMXXVI: two thousands, two tens, one five and one one. 1994 is MCMXCIV.
Assumptions and input details
A defined modern subtractive convention is used, with case-insensitive ASCII letters. Historical additive spellings, clock-face IIII, Unicode numeral glyphs, overbars, zero, negatives and values above 3999 are excluded rather than guessed.
References: Language Portal of Canada: Roman numeral conventions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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