Roman Numerals (ROMAN & ARABIC)

Excel Formulas › Math

All versionsROMANARABIC

ROMAN turns an ordinary number into Roman numerals — for copyright years, outline numbering, or chapter headings — and ARABIC converts them back to regular numbers.


Quick formula: to convert a number to Roman numerals:
=ROMAN(A2)
ROMAN(2026) = MMXXVI. Reverse with =ARABIC("MMXXVI") = 2026.

Functions used (tap for the full reference guide):

The example

Numbers as Roman numerals and back.

AB
1NumberRoman
24IV
32026MMXXVI
449XLIX

The formula

Number to Roman:

=ROMAN(2026) // → MMXXVI

How it works

Two functions, opposite directions:

  1. ROMAN(n) converts a number (1–3999) into its Roman-numeral string — 4 → IV, 2026 → MMXXVI.
  2. ARABIC(text) reverses it: ARABIC("XLIX") → 49.
  3. ROMAN has an optional “form” argument (0–4) for more concise classic styles — 0 is the standard form most people want.
  4. The result of ROMAN is text; ARABIC gives back a real number you can calculate with.

Common use: copyright and edition lines (“© MMXXVI”), and outline/heading numbering. Pair with TEXT or concatenation to build the label.

Try it: interactive demo

Live demo

Enter a number 1-3999.

Roman:

Variations

Roman back to a number

ARABIC reverses it:

=ARABIC("MMXXVI") → 2026

Concise classic form

The form argument shortens it:

=ROMAN(499, 4)

Copyright line

Build a label:

="© " & ROMAN(YEAR(TODAY()))

Pitfalls & errors

Range is 1 to 3999. ROMAN can’t represent 0, negatives, or 4000+. Those return #VALUE!.

ARABIC needs valid Roman text. Garbage in (invalid numeral strings) gives errors or wrong values. It does accept lowercase and a leading minus.

Decimals are truncated. ROMAN(4.9) treats it as 4 (IV) — only the integer part is used.

Practice workbook

📊
Download the free Roman Numerals (ROMAN & ARABIC) practice workbook
Numbers to Roman (ROMAN) shown live, plus ARABIC and copyright-line variants, and 4 challenges with answers. No sign-up required.

Frequently asked questions

How do I convert a number to Roman numerals in Excel?
Use =ROMAN(n), e.g. =ROMAN(2026) returns MMXXVI. It works for numbers 1 to 3999.
How do I convert Roman numerals back to a number?
Use =ARABIC("MMXXVI"), which returns 2026. ARABIC accepts upper or lower case.
Why does ROMAN return #VALUE!?
The number is outside the supported 1-3999 range, or is zero/negative. Roman numerals can't represent those values.

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Related formulas: Convert between bases · Combinations & permutations · Convert units (CONVERT)

Function references: ROMAN · ARABIC