Roman Numeral Date Converter

Turn any calendar date into Roman numerals — the classic style used on cornerstones, monuments, film credits, and tattoos. Enter the day, month, and year to get each part converted separately.

How to use this calculator

Type a day (1–31), a month (1–12), and a year (1–3999), then press Calculate. The page updates instantly as you type. Invalid entries — like February 30 or year 0 — show an error instead of a result.

How it works

Each field is converted separately using standard subtractive Roman notation (I, V, X, L, C, D, M with IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900). Day range 1–31, month 1–12, year 1–3999.

Worked example

Date 23 / 10 / 2026: 23 → XXIII; 10 → X; 2026 → MM (2000) + XX (20) + VI (6) = MMXXVI. Full date: XXIII · X · MMXXVI.

Reference data

This page relies on no external dataset — the conversion is pure numeral-system math. The standard symbol values used by the converter are:

Standard Roman numeral symbol values (constants, not external data)

Symbol	Value
I	1
V	5
X	10
L	50
C	100
D	500
M	1,000

Source: standard Roman numeral symbol values (derivation constants, not external data; 2026).

Method & sources

The converter greedily subtracts the largest available Roman value from the number and appends the matching symbol, repeating until nothing remains — this produces the standard subtractive form (e.g., 4 becomes IV, not IIII). Each date field is converted independently, so no calendar arithmetic is involved.

• Roman numeral rules and symbol set: Wikipedia — Roman numerals
• No external dataset is used; the symbol values above are the derivation constants.