# How Hard Is a Chinese Text? Measuring Difficulty by HSK Character Coverage

URL: https://fulinlabs.com/blog/how-hard-is-a-chinese-text-coverage-method-2026/
Published: 2026-10-03
Product: hsk-studio
Summary: A reproducible way to estimate how hard a Chinese passage is: the share of its characters that fall within each HSK level, worked through on eight published example passages.

“What level is this text?” sounds like a question with an answer. It has several, depending on
what you count. This post uses one of the simplest defensible measures — **character coverage** —
and works it through on eight example passages whose results you can download and check.

I build [HSK Studio](/projects/hsk-studio/), so I have a stake in text analysis tools. The method
below does not need any of them: it is arithmetic you can do with a word list.

## The method

1. Take the passage and keep only the Han (Chinese) characters. Punctuation, digits, Latin
   letters and emoji count toward total length but not toward coverage.
2. Count **occurrences**, not unique characters. A character that appears five times counts five
   times.
3. For each HSK level from 1 to 6, find what share of those occurrences belong to that level or
   an easier one. That is the **cumulative coverage**.
4. Pick a threshold. The reference analysis uses 90%: the **screening level** is the lowest level
   whose cumulative coverage reaches it.

The word lists are the official HSK 2012 lists, so “HSK 3” here means the 2012 syllabus, not the
newer 3.0 standard.

## Three worked examples

These come from the [Chinese text analysis reference benchmark](/tools/chinese-text-analyzer/#reference-benchmark),
a set of eight original diagnostic passages. They are small and constructed; they show how the
method behaves, not how typical Chinese text is distributed.

| Passage | Han characters | HSK 1 | HSK 1–2 | HSK 1–3 | HSK 1–4 | HSK 1–5 | Screening level |
| --- | ---: | ---: | ---: | ---: | ---: | ---: | ---: |
| Commute and reading | 51 | 51.0% | 80.4% | 96.1% | 100% | 100% | 3 |
| Technical vocabulary | 27 | 29.6% | 44.4% | 66.7% | 88.9% | 100% | 5 |
| Repetition and one rare character | 10 | 90.0% | 90.0% | 90.0% | 90.0% | 90.0% | 1 |

**The commute passage** is everyday Chinese: coffee, the subway, reading news on a phone. It
needs HSK 3 to pass 90%, with 8 of its 51 characters at that level and two (猜 and 篇) above
HSK 3. The two characters above the screening level are the ones worth looking up before
reading.

**The technical passage** is about half the length and has a very different profile. Only 44%
of its characters are within HSK 1–2, and it takes HSK 5 to reach full coverage because of its
specialist vocabulary (protein, gene and machine-learning terms). Two short passages can sit
two levels apart.

**The repetition example** is the one that should make you suspicious of any single number. The
text is nine copies of 我 followed by one very rare character, 龘. It reaches 90% at HSK 1
because coverage counts occurrences. The text is not easy; one character in ten is not in any
list, and that one is the whole difficulty. Real text rarely looks like this, but long texts with
a repeated name or term can drift in the same direction.

## Two edge cases that need a rule

**A rare character on its own** — a single Han character outside the bundled lists — has 0%
coverage at every level, so it receives no level rather than “above HSK 6”. **A passage with no
Han at all** also receives no level. Claiming a level for text that has no Chinese in it would
be false precision.

**Traditional characters.** The HSK 2012 lists are simplified. The benchmark’s traditional
version of the everyday sentence normalises four characters and then lands on exactly the same
coverage as the simplified sentence. If a tool scores traditional text without normalising, it
is reporting characters it does not recognise as unknown, not as hard.

## What the number does not tell you

- **Characters are not words.** 学习 is made of two familiar characters and is also a single
  word you may or may not know. The method does not look at word boundaries.
- **Coverage is not comprehension.** 96% of characters inside your level leaves about one in
  twenty-five unfamiliar, and grammar, idiom and topic knowledge are not measured at all.
- **Short texts are noisy.** A twelve-character sentence moves by about nine percentage points with
  one character. Use longer samples before you trust the shape.
- **90% is a convention.** It is a stated threshold in this analysis, not a research-validated
  point of comfortable reading. Change the threshold and the levels move.

So use the number to decide whether to *try* a text, and let the first paragraph decide
whether to keep going. For a longer treatment of choosing material, see
[how to choose Chinese reading material for your HSK level](/blog/how-to-choose-chinese-reading-material-hsk-2026/).

## Check it yourself

- Paste a passage into the [Chinese text analyzer](/tools/chinese-text-analyzer/) to see its
  coverage at each level and the characters above your level. It runs in your browser, so nothing
  is uploaded.
- Download the benchmark as CSV or JSON from the [open datasets page](/data/). The JSON includes
  every passage, and the CSV carries a SHA-256 for each so a cited result can be reproduced
  exactly. Both are CC BY 4.0.
- If your count differs from the published one, send the passage to
  [hello@fulinlabs.com](mailto:hello@fulinlabs.com). A discrepancy is more useful to me than
  agreement.

## FAQ

### How do you measure how hard a Chinese text is?

One reproducible way is HSK character coverage: count every Chinese character occurrence in the passage, then calculate what share falls inside HSK 1, HSK 1–2, HSK 1–3 and so on. The lowest level whose cumulative share reaches a chosen threshold, such as 90%, is a screening level for the text. It estimates vocabulary exposure, not whether you will understand the passage.

### Does a text at HSK 3 coverage mean an HSK 3 learner can read it?

No. Coverage counts characters, not words, grammar, idioms or topic knowledge, and a 90% share still leaves roughly one character in ten unfamiliar. Treat it as a first filter before you try the text, then judge by reading a paragraph.

### Why do repeated characters change the result?

Coverage counts occurrences, so a very common character repeated many times lifts the share even when the passage also contains an unknown one. In the published example, nine occurrences of 我 and one rare character reach 90% at HSK 1.

### Are traditional characters handled?

The HSK 2012 lists are written in simplified characters, so traditional text has to be normalised to simplified first. The analyzer reports how many characters it normalised, and the published traditional-character example normalises four.
