Why do many clocks show IIII instead of IV?
Look closely at a clock with Roman numerals and the four often catches your eye. Instead of the expected IV it shows IIII. According to today's rules that is actually wrong, because at most three identical symbols may stand in a row. Still, IIII is so widespread on clock faces that many people consider it the normal notation. Behind it lies no oversight but a mix of history, design and tradition.
The Romans themselves often wrote IIII
The strict subtractive notation with IV and IX is younger than many think. On Roman inscriptions, four is frequently found as IIII and nine as VIIII. Both variants existed side by side for a long time. Only gradually did the shorter subtractive form become the standard. Clock faces therefore preserve an older notation that was perfectly correct at the time.
Visual balance on the dial
The most frequently cited explanation is about design. Opposite the IIII stands the VIII. Both numerals are wide and consist of four symbols. With IV, the left side of the dial would look noticeably lighter than the right. In addition, IIII divides the dial into three visual zones: from I to IIII there are only I symbols, from V to VIII the V is added, and from IX to XII the X dominates. This looks calm and even.
Other explanations and legends
Other stories circulate around the IIII. One says that with IIII the numerals of a dial could be cast in four identical sets of five I, one V and one X each, which would have simplified production. Another legend claims IV was avoided because it resembled the first letters of the Roman god Jupiter, written in Latin as IVPPITER. There is no firm evidence for these explanations. But they show how long the question has intrigued people.
So is IIII on a clock wrong?
By today's rules for writing and calculating with Roman numerals, four is IV. Anyone writing a year, a chapter number or a date should therefore use IV. On clock faces, however, IIII is an accepted tradition and not a mistake. Incidentally, there are also clocks with IV — both variants are available. Our Roman numerals converter follows today's standard: if you type IIII, it points out that four is written IV.
Reading the time in Roman numerals
A dial with Roman numerals shows the numbers from I to XII. The minutes are usually marked only as ticks. The basic rules help with reading: if a smaller symbol stands before a larger one, it is subtracted (IX = 9); if it stands after, it is added (XI = 11). Once you have internalised this, you can read Roman dials just as quickly as Arabic ones.
| Hour | Common on clocks | Today's standard |
|---|---|---|
| 1 | I | I |
| 4 | IIII | IV |
| 6 | VI | VI |
| 9 | IX | IX |
| 11 | XI | XI |
| 12 | XII | XII |
Notably, nine is almost always written IX even on clocks, not VIIII. The exception usually concerns only the four.
Roman numerals on buildings and tower clocks
You will also come across Roman numerals on tower clocks, sundials and facades, often together with a year above the entrance. How to decipher such years is shown in the article Years in Roman numerals. The complete rules, including the subtraction rule, are explained in the main article Reading and writing Roman numerals.