Standard form
Modern Roman numeral calculators usually enforce subtractive notation such as IV for 4 and CM for 900, instead of nonstandard repeated forms.
Example
2026 is MMXXVI: MM for 2000, XX for 20 and VI for 6.
Input tips
Use the standard symbols I, V, X, L, C, D and M. For conversion back to decimal, enter a valid Roman numeral rather than a repeated nonstandard form.
Limitations
This calculator uses the common modern range from 1 to 3999. Historical inscriptions can use variant forms that are not accepted here.
Last reviewed: 2026-05-17