4 in Roman Numerals = IV

4 in Roman numerals is IV. The I sits before the V, which means you subtract one from five rather than adding it.

What is 4 in Roman numerals?

4 = IVFour

IV is V (5) minus I (1). Placing a smaller symbol in front of a larger one flips it from addition to subtraction, and the pair is read as a single unit worth four.

The same pair works one place value up each time: IX is nine, XL is forty, XC is ninety, CD is four hundred, CM is nine hundred. Learn IV and you have learned all six subtractive pairs.

How IV is formed

Reading left to right, 4 breaks into these additive parts. Each Roman symbol is added in turn to reach the total.

IV4

IV = 4 = 4.

Why 4 is written IV

The obvious spelling, IIII, breaks the rule that no symbol repeats more than three times. Rome itself was not strict about this: IIII appears widely in ancient inscriptions, and the subtractive IV only became the standard form much later. That history is why clock faces are the way they are, and why 4 is by some distance the most looked-up value in the whole system.

Where 4 in Roman numerals is used

Clock and watch dials: Most Roman-numeral dials print four as IIII rather than IV, for visual balance against the VIII opposite it. The Great Clock at Westminster is the famous exception and uses IV, so both forms are in daily view on public clocks.
Regnal names: Henry IV of England and Henry IV of France both carry the numeral, and each is read aloud as the Fourth rather than as I-V.
Chapters and acts: Act IV is the turning point in a five-act play, the structure Shakespeare's tragedies follow, so the numeral turns up constantly in scripts and study editions.
Super Bowl IV: Played in January 1970, the last championship before the AFL and NFL merger completed, and an early example of the numbering that now sends people looking these values up.

Common mistakes writing 4 in Roman numerals

IIII is wrong. Traditional on clock dials and common in antiquity, but not the standard modern numeral. Written anywhere other than a watch face it will read as an error.
IIV is wrong. Subtraction only ever uses a single symbol before the larger one. Two strokes in front of a V is not a valid construction, and it would in any case describe three, not four.

Good to know about 4

Four is the single most searched Roman numeral, largely because clock faces so often use IIII instead of IV.
On a clock or watch face, 4 o'clock is shown as IV.

Convert another number

Number

Roman numeral

4 is written IV in Roman numerals.

Frequently asked questions

Why do clocks use IIII instead of IV?

Clock dials use IIII for symmetry: it gives the left half of the dial a heavier block of strokes that balances the VIII sitting opposite, and it means the first four hours all read as plain I forms. It is a typographic tradition, not a rule of the numeral system, and IV remains the correct standard spelling of four.

How do you write 4 in Roman numerals?

Write 4 as IV, combining IV. Start from the largest value that fits and work down until nothing is left over.

Why is 4 not written IIII?

IV uses the subtractive rule: a smaller symbol placed before a larger one is taken away, so you never repeat a symbol four times. IIII breaks that rule, which is why IV is the only correct form.

Is IV the 4 you see on a clock?

Yes. 4 o'clock is written IV on Roman-numeral clock and watch faces, with the one quirk that many dials print four as IIII rather than IV out of tradition.

What are 3 and 5 in Roman numerals?

3 is III and 5 is V. Neighbouring numbers often change length in surprising ways, which is why each has its own page.

Related conversions

40 in Roman numerals is XL, the same digit one place value up.
400 in Roman numerals is CD, the same digit two place values up.
8 in Roman numerals is VIII, double 4.
5 in Roman numerals is V, one more than 4.
3 in Roman numerals is III, one less than 4.
104 in Roman numerals is CIV, 4 in the hundreds.