How to Write BC, BCE, AD and CE Years in Roman Numerals

For example:

• 44 BC becomes XLIV BC.
• 44 BCE becomes XLIV BCE.
• AD 476 becomes AD CDLXXVI.
• 476 CE becomes CDLXXVI CE.

The era label changes how the year is described, not how its number is converted.

The most important boundary rule is that conventional BC/AD and BCE/CE chronology has no year zero. The sequence moves directly from 1 BC or 1 BCE to AD 1 or 1 CE.

Key takeaways

• Convert the positive year number, then retain the era label.
• 44 BC and 44 BCE both use XLIV.
• AD 476 and 476 CE both use CDLXXVI.
• BC and BCE years count down as they approach the era boundary.
• Conventional historical chronology has no year zero.
• Astronomical year 0 corresponds to 1 BCE, but it belongs to a different numbering system.
• A minus sign is not an ordinary historical substitute for BC or BCE.
• XLIV BC is modern era notation, not an ancient Roman date formula.
• Placement and punctuation can vary between style guides and languages.

Convert the year, then add the era

The Roman numeral represents the positive year number. The era label tells the reader which chronological era the year belongs to.

The conversion method is unchanged:

476 = 400 + 70 + 6
400 = CD
70 = LXX
6 = VI
476 = CDLXXVI

The era remains separate:

AD 476 = AD CDLXXVI
476 CE = CDLXXVI CE

Without an era label, CDLXXVI shows only the number 476. It does not distinguish 476 BCE from 476 CE.

BC and BCE use the same year numbers

BC means “Before Christ”. BCE means “Before the Common Era”.

They refer to the same numbered years:

• 44 BC uses XLIV;
• 44 BCE also uses XLIV.

AD, from the Latin anno Domini, and CE, “Common Era”, likewise refer to the same numbered years:

• AD 476 uses CDLXXVI;
• 476 CE also uses CDLXXVI.

Use one era system consistently unless quoting a source that uses another.

Where should the era label go?

Traditional English styling normally places AD before the year:

AD CDLXXVI

BC, BCE and CE normally follow it:

XLIV BC
XLIV BCE
CDLXXVI CE

Institutional and language-specific styles may differ over placement, full stops, small capitals and spacing. These are editorial choices rather than Roman-numeral rules.

Follow the style required by the publication, institution or project and apply it consistently.

There is no conventional historical year zero

The sequence crosses the era boundary like this:

2 BC → 1 BC → AD 1 → AD 2

Using BCE and CE:

2 BCE → 1 BCE → 1 CE → 2 CE

There is no historical year 0 between 1 BCE and 1 CE.

The two adjacent years therefore both use the Roman numeral I:

1 BCE = I BCE
1 CE = I CE

The era label is essential because I alone cannot distinguish them.

Why BCE years appear to run backwards

BCE and BC numbers become smaller as they approach the era boundary:

44 BCE → 43 BCE → 42 BCE

A larger BCE number is further in the past. For example, 100 BCE comes before 44 BCE, while 1 BCE is the final year before 1 CE.

The Roman conversion still uses the positive number shown:

100 BCE = C BCE
44 BCE = XLIV BCE
1 BCE = I BCE

Do not reverse the numeral or apply a special conversion rule. The direction comes from the chronology.

Astronomical year numbering is different

Astronomers and some technical systems use a continuous numbering sequence that includes year 0.

Astronomical year 0 corresponds to the historical year 1 BCE. Astronomical year −1 corresponds to 2 BCE.

Because astronomical numbering includes year 0, every BCE year shifts by one:

44 BCE corresponds to astronomical year −43

This does not create an extra historical year. It renumbers the same sequence for calculation.

A minus sign belongs to astronomical numbering, not to ordinary Roman-numeral era notation. −XLIV is therefore not the standard historical way to write 44 BCE.

For general historical writing, use XLIV BC or XLIV BCE.

BCE centuries

BCE centuries also run backwards towards 1 BCE:

• first century BCE: 100 BCE to 1 BCE;
• second century BCE: 200 BCE to 101 BCE;
• third century BCE: 300 BCE to 201 BCE.

Therefore, 44 BCE belongs to the first century BCE.

The year itself remains XLIV. Full century and millennium calculations belong in the dedicated century guide.

Is XLIV BC an ancient Roman date?

No.

XLIV BC is a modern combination of a Roman numeral year and a later era label. Ancient Romans did not describe their own years as BC or BCE.

They used other systems, including the names of officeholders, years counted from particular reference points and calendar expressions based on the Kalends, Nones and Ides.

A modern writer can use XLIV BC to present 44 BC in Roman numerals. That does not make it an authentic ancient Roman dating formula.

This distinction matters for historical displays, inscriptions, tattoos and engravings.

Worked examples

753 BC

753 = 700 + 50 + 3
700 = DCC
50 = L
3 = III
753 = DCCLIII

Result:

DCCLIII BC
DCCLIII BCE

AD 1066

1066 = 1,000 + 60 + 6
1,000 = M
60 = LX
6 = VI
1066 = MLXVI

Result:

AD MLXVI
MLXVI CE

Quick verification checklist

Before using an era-labelled Roman numeral year:

1. Confirm the positive year number.
2. Convert it using standard Roman numeral rules.
3. Retain the BC, BCE, AD or CE label.
4. Do not insert a historical year zero.
5. Do not use a minus sign unless you deliberately mean astronomical numbering.
6. Follow one style for era placement and punctuation.
7. Check that any BCE century range has not been reversed.
8. Remember that modern era notation is not ancient Roman calendar language.

Continue exploring

• Roman Numerals for Years
• Roman Numerals for Centuries and Millennia
• Can Roman Numerals Represent Zero, Negative Numbers and Decimals?
• How Romans Wrote Dates: Kalends, Nones and Ides
• Roman Numeral Date Formats Explained