Estimate Your Vocabulary Range
The free adaptive test returns an indicative model range and review list. It does not produce an exact inventory, official CEFR placement, or validated population percentile.
Take the vocabulary test →Contents
What Can a Vocabulary-Test Result Tell You?
A vocabulary-size test samples a small set of items and uses a model to estimate a broader range. Treat the result as a directional snapshot: useful for choosing material, identifying weak areas, and tracking repeated results under similar conditions—not as a count of every word you know.
| The result can help with | The result cannot establish |
|---|---|
| A broad receptive-vocabulary range | An exact inventory of known words |
| A review list from sampled items | An official exam score or percentile |
| Comparing your own repeated attempts | A diagnosis or independently validated CEFR placement |
What Does This Test Measure?
The test focuses on receptive recognition and meaning selection. It does not measure speaking, writing, pronunciation, grammar, or every sense of a word. Its reported unit is an internal vocabulary-range estimate and should not be assumed equivalent to lemma or word-family totals from an external study.
| Construct | Included? | How |
|---|---|---|
| Word recognition | Yes | Real words mixed with plausible nonwords |
| Meaning selection | Yes | Multiple-choice verification |
| Productive vocabulary | No | No free speaking or writing task |
| Official CEFR or exam ability | No | Requires a validated multi-skill assessment |
How the Two Test Phases Work
Phase i is a recognition screen. You mark familiar words while decoy nonwords help detect overclaiming. Phase ii verifies a sample through meaning questions and adapts item selection as the model updates its estimate. Both phases are sampling procedures; neither can enumerate a complete personal lexicon.
How to Interpret Your Estimated Range
Read the range together with the decoy rate, verified answers, and review list. A high decoy rate means the recognition screen was too permissive. A narrow-looking model interval does not substitute for real-world validation.
| Signal | Practical interpretation |
|---|---|
| Estimated range | Central model output from the sampled items |
| Decoy overclaim rate | Quality check on self-reported recognition |
| Verified correct answers | Evidence from the meaning-selection sample |
| Review list | Words worth checking or studying next |
Important limitation: the scoring implementation has not yet been independently validated against a representative external criterion sample. Read the validation report before comparing the estimate with published population data.
What Do the CEFR-Oriented Labels Mean?
The learner track uses CEFR-oriented vocabulary labels to organize feedback. CEFR itself describes what a person can do across language skills; it does not define official vocabulary-size cutoffs. A vocabulary-only result is therefore study guidance, not a CEFR certificate.
| Label use | Appropriate interpretation |
|---|---|
| A1–A2 oriented | Focus on high-frequency everyday vocabulary |
| B1–B2 oriented | Expand independent reading and general academic vocabulary |
| C1–C2 oriented | Work on low-frequency, nuanced, and domain-specific vocabulary |
| Official CEFR level | Use a validated assessment covering multiple skills |
How Does This Differ From Average-Vocabulary Research?
This page answers a self-estimation question: how to take the test and interpret its output. For population estimates by age and education—including the difference between 42,000 lemmas and 11,100 word families—see the research guide to average vocabulary size. Do not transfer a percentile or label between instruments unless a validation study supports that comparison.
Method and Validation Status
The adaptive engine uses a 2-parameter logistic item-response model, Bayesian Expected A Posteriori updates, and Fisher Information for item selection. Its internal uncertainty controls model behavior; it is not a proven real-world percentage error. The methodology page documents the design, and the validation report records current evidence and limitations.
What Should You Do After the Test?
- Review missed and uncertain items rather than focusing only on the headline range.
- Read material near your comfortable level and note recurring unknown words.
- Use spaced repetition for a small, relevant review set.
- Repeat under similar conditions if you want to track directional change.
Evidence Used for Context
Published research informs the vocabulary domain, but it does not validate this implementation. The most relevant context is Brysbaert et al. (2016) for lemma and word-family definitions and Nation (2006) for text-coverage thresholds.
Ready to Get an Indicative Range?
Take the test, then interpret the range together with the decoy rate, verified answers, and review list.
Start the vocabulary test →Frequently Asked Questions
How can I find out roughly how many words I know?
Use a vocabulary-size test as a sampling tool. This site provides an indicative range based on recognition and meaning-selection items; it does not count every word in your lexicon.
Is the result an exact vocabulary count?
No. It is a model estimate from sampled items. Item coverage, guessing, overclaiming, and the definition of “word” all affect the output.
Is the CEFR label official?
No. The label is vocabulary-oriented study guidance. Official CEFR assessment requires validated evidence across relevant language skills.
Can I compare my result with published adult averages?
Only cautiously. Published studies may count lemmas or word families and use different word lists and tasks. The population research page keeps those units separate.
What does the decoy rate mean?
Decoys are plausible nonwords. Selecting them suggests overclaiming during recognition, so the model uses that signal as a quality check.
Has this test been independently validated?
Not yet against a representative external criterion sample. The validation report describes completed checks and remaining work.