The infinity symbol was introduced in 1655 by John Wallis. How it got from a mathematics paper to a tattoo is a longer story.
The short version
Start here if you only have one minute. The full guide below explains each point.
1655, John Wallis
The first known use, in a work on conic sections.
Nobody knows why
Wallis left no explanation for the shape.
The romantic meaning is modern
It comes from jewellery, not mathematics.
01
1655, and one page
The English mathematician John Wallis used the lemniscate for infinity in De sectionibus conicis, published in 1655. It is the first known use.
He gave no explanation. Every account of why he chose that shape is a later guess, and the honest position is that nobody knows.
02
The theories, and what they are worth
One suggestion is a variant of the Roman numeral for a thousand, which was sometimes used to mean many. Another is the Greek letter omega, the last letter and so an ending.
Neither has documentary support from Wallis himself. They are plausible reconstructions rather than established history.
✦Wallis never wrote down his reasoning. Any confident story about the symbol's origin is filling a gap in the record.
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It took two centuries to settle
Adoption was slow. For much of the eighteenth and nineteenth centuries mathematicians used a variety of notations for unbounded quantities.
It became standard alongside the formalisation of limits in the nineteenth century, when a single agreed notation started to matter.
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What it means in mathematics
It is not a number. It is notation for a quantity growing without bound, and it behaves according to the rules of the specific system using it.
That is why arithmetic with it is undefined in ordinary mathematics. The symbol marks a limit rather than a value.
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How it left mathematics
The modern decorative meaning of endless love or eternity is twentieth century and owes nothing to Wallis.
It spread through jewellery and tattoo design in the 2000s, where the unbroken continuous line reads as permanence regardless of the mathematics.
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In Unicode
It was encoded as U+221E INFINITY in Unicode 1.0 in 1991, in the Mathematical Operators block.
The block placement reflects its origin. Its decorative use came later and the standard, as always, records the character rather than the fashion.
The symbol's documented timeline
Only the first and last rows are firmly dated. The middle two describe gradual shifts rather than events.
| Date | Event |
|---|---|
| 1655 | John Wallis uses the lemniscate in De sectionibus conicis |
| 1700s–1800s | Competing notations for unbounded quantities remain in use |
| 1800s | Settles as standard alongside the formalisation of limits |
| 1900s | Decorative meaning of eternity emerges outside mathematics |
| 1991 | Encoded as U+221E in Unicode 1.0 |
The gap between 1655 and general adoption is the part most accounts skip. The symbol was not immediately accepted; it competed for roughly two centuries.
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Copy the symbols discussed in this guide
This guide explains the topic. Use math symbols for the main copyable set, compare it with aesthetic symbols, and browse technical symbols for another useful angle. Each collection includes searchable Unicode names and HTML references.
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Questions, answered
Who invented the infinity symbol?+
John Wallis, an English mathematician, in a 1655 work on conic sections. He never recorded why he chose that shape.
Does the infinity symbol mean eternal love?+
Not originally. That meaning is twentieth century and comes from jewellery and tattoo design, not from mathematics.
Is infinity a number?+
No. It is notation for growth without bound, which is why ordinary arithmetic with it is undefined.
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Sources and review notes
Character identities were checked against Unicode charts; contextual guidance distinguishes standardized names from broader cultural use.