%, ‰, and ‱ all express ratios, but each uses a different denominator: hundred, thousand, and ten thousand. The symbols look related because the ideas are related; the values are not interchangeable.
Changing only the sign can therefore change the quantity by a factor of ten or one hundred. These marks fit naturally among other measurement symbols, even though they are common in finance, statistics, and everyday reporting.
Three denominators behind three signs
| Symbol | Unicode name | Code point | Meaning | One unit equals |
|---|---|---|---|---|
| % | PERCENT SIGN | U+0025 | Per hundred | 0.01 |
| ‰ | PER MILLE SIGN | U+2030 | Per thousand | 0.001 |
| ‱ | PER TEN THOUSAND SIGN | U+2031 | Per ten thousand | 0.0001 |
What percent % means
Percent expresses a ratio relative to 100. 5% means 5/100, which is 0.05 as a decimal. The symbol is used across finance, statistics, science, interfaces, and ordinary prose.
The SI Brochure explicitly allows the internationally recognized percent symbol to be used with the SI. In SI-style technical writing it places a space between the number and the symbol, as in 5 %. Many newspapers, websites, and house styles instead write 5%. That typographic choice does not change the underlying U+0025 character.
What per mille ‰ means
Per mille means “per thousand.” 5‰ is 5/1000, or 0.005. Unicode names U+2030 PER MILLE SIGN and notes uses such as blood-alcohol measurements and salinity.
The relationship to percent is simple: 1% equals 10‰. A value of 0.5% therefore equals 5‰. Choosing per mille can make a small ratio easier to read without writing several leading zeros.
What per ten thousand ‱ means
U+2031 PER TEN THOUSAND SIGN represents one part in 10,000. Unicode also gives the alias permyriad and notes that the sign is rarely used.
One ‱ equals 0.0001 as a decimal, which is 0.01%. Numerically, that is also the size of one basis point. Finance usually writes basis points as bp rather than using ‱, so the two concepts can be equivalent in scale without being the same textual notation.
One basis point is therefore one part in ten thousand, but bp and ‱ are different notations. When transcribing a source, preserve the form that was actually used rather than silently swapping one for the other.
One quantity, three ways to display it
| Percent | Per mille | Per ten thousand | Decimal |
|---|---|---|---|
| 1% | 10‰ | 100‱ | 0.01 |
| 0.1% | 1‰ | 10‱ | 0.001 |
| 0.01% | 0.1‰ | 1‱ | 0.0001 |
A ratio of 0.035 can be written as 3.5%, 35‰, or 350‱. The underlying quantity is unchanged; only the scale used to display it is different.
Conversion is arithmetic, not typography. If you swap the sign without rescaling the number, you change the value: 3.5% and 3.5‰ are a factor of ten apart.
U+2030 and U+2031 are not a percent sign plus extra circles assembled with combining marks. They are independently encoded characters. A font controls their exact drawing, but the underlying text identity remains distinct.
This matters when copying, searching, parsing, or validating text. A parser should inspect the actual code point rather than trying to infer the scale from the number of small circles in the glyph.
Spacing is not governed by one universal rule
The current SI Brochure gives explicit guidance for the percent sign: when % is used with the SI, a space separates the number and the symbol. It does not provide the same specific rule for U+2030 ‰ or U+2031 ‱ in that passage.
For per mille or per ten thousand, follow the standard, regulation, scientific convention, or house style that governs the document. Do not assume that a rule written specifically for % automatically settles every related ratio symbol in every field.
A separate trap: percent change vs percentage points
A separate source of confusion comes from the language around percentages. If a rate rises from 10% to 12%, the difference is 2 percentage points. Relative to the original 10%, the increase is 20%.
The symbol itself cannot tell the reader which comparison is intended. Clear wording is necessary whenever a report moves between absolute percentage-point differences and relative percentage changes.
Keep the value separate from its display
For calculations, keeping the underlying ratio separate from its display format avoids a lot of confusion. The value 0.001 can then be rendered as 0.1%, 1‰, or another agreed notation without altering the stored quantity.
If exact source text matters, store the original sign too. That keeps two questions separate: what numerical ratio does the data represent, and how did the author choose to display it?
Choose the scale your audience will read correctly
Use % for per hundred, ‰ for per thousand, and ‱ for per ten thousand. The best choice is the one your field expects and your audience can read without stopping to decode it.
If the audience is unlikely to recognize ‱, writing “per ten thousand,” using a decimal or percentage, or using a domain-standard term such as basis points may be clearer than relying on an uncommon symbol.