Tools

Chalder Fatigue Scale (CFQ-11)

The 11-item fatigue questionnaire used across UK ME/CFS and long COVID services

The Chalder Fatigue Questionnaire was developed at King's College London and published by Trudie Chalder and colleagues in 1993. The 11-item version is the fatigue measure you are most likely to meet in UK research and in NHS ME/CFS and long COVID clinics, and has been used in long COVID studies. It asks about physical fatigue (7 items) and mental fatigue (4 items) over the past month, and if you have been tired for longer than that, compared with how you felt when you were last well.

It has two scoring systems, and this page gives you both. Likert scoring rates each answer 0–3 for a total of 0–33 and is the more sensitive to change. Bimodal scoring counts each item as either absent (0) or present (1) for a total of 0–11, with 4 or more the conventional threshold for clinically significant fatigue. Papers and clinic letters quote whichever they prefer, so it helps to know your score on both.

If your fatigue gets disproportionately worse after activity, the DSQ-PEM characterises that pattern specifically. The Fatigue Severity Scale measures the impact of fatigue on functioning rather than the symptom itself, and the FUNCAP profiles what activities cost you.

This is not a diagnostic tool. A high score indicates fatigue as a symptom; it does not tell you the cause, and fatigue has many. The bimodal threshold was derived against a psychiatric interview measure of fatigue, not against any diagnosis. Discuss your results with your doctor. Based on: Chalder T, Berelowitz G, Pawlikowska T, et al. Development of a fatigue scale. J Psychosom Res. 1993;37(2):147–153; and Cella M, Chalder T. Measuring fatigue in clinical and community settings. J Psychosom Res. 2010;69(1):17–22. The Chalder Fatigue Scale is the work of its authors at King's College London; this page provides an interactive scoring aid for personal, non-commercial use.

These questions are about any problems you have had with feeling tired, weak, or lacking in energy in the last month. If you have been feeling tired for a long while, compare yourself with how you felt when you were last well. Choose the answer that applies to you most closely.

Physical fatigue

1. Do you have problems with tiredness?

2. Do you need to rest more?

3. Do you feel sleepy or drowsy?

4. Do you have problems starting things?

5. Do you lack energy?

6. Do you have less strength in your muscles?

7. Do you feel weak?

Mental fatigue

8. Do you have difficulty concentrating?

9. Do you make slips of the tongue when speaking?

10. Do you find it more difficult to find the correct word?

11. How is your memory?

Understanding your Chalder Fatigue Scale score

What the score measures

Each of the 11 questions has four answers. Likert scoring gives them 0, 1, 2 and 3, for a total from 0 to 33, with a physical fatigue subscale (questions 1 to 7, 0 to 21) and a mental fatigue subscale (questions 8 to 11, 0 to 12). Bimodal scoring counts the first two answers as 0 and the last two as 1, for a total from 0 to 11. On both, higher means more fatigue.

It was developed in UK general practice, where its questions split into physical and mental fatigue (Chalder et al. 1993); the same split appeared in a later study (Cella and Chalder 2010).

Score bands

In a UK study, 1,615 adults attending general practice averaged 14.2 on Likert scoring, with a standard deviation of 4.6, and 361 people with chronic fatigue syndrome averaged 24.4. On bimodal scoring, 4 or more is the conventional cut-off for significant fatigue; in a Norwegian general population survey, 22% scored at that level.

Likert reference points (0–33)
ScoreWhat it isSource
14.2Average of 1,615 adults attending UK general practiceCella and Chalder 2010
15.1Average of 456 non-hospitalised adults about four months after COVID-19, in NorwayStavem et al. 2021
24.4Average of 361 people with chronic fatigue syndromeCella and Chalder 2010

There are no published Likert bands. After COVID-19, 46% of the Norwegian group scored 4 or more on bimodal scoring (Stavem et al. 2021).

It means you chose one of the two higher answers on at least four questions. In the 1993 study that developed the scale, then 14 questions long, a cut-off between 3 and 4, which the authors called arbitrary, agreed with a psychiatric interview's rating of fatigue with about 75% sensitivity and 75% specificity. It marks significant fatigue, not any particular condition.

What a change in score means

No minimal important change has been published for individuals, so a difference of a point or two between two results may not mean much on its own. The questions cover the past month, so repeat it monthly and look for a steady shift over several results.

The comparison point, "when you were last well", does not move, so after years of illness you are still comparing with your healthy self.

What it does not measure

No. It measures how much fatigue you have compared with when you were last well, not why. It does not ask about post-exertional malaise, which is central to ME/CFS, and fatigue has many causes that a doctor will want to rule out.

The Fatigue Severity Scale measures how much fatigue gets in the way. For worsening after effort, use the DSQ-PEM and see the post-exertional malaise explainer.

Taking this to your GP or consultant

Bring the Likert total, the physical and mental subscores, the bimodal score, the date and the trend from your saved results. Papers and clinic letters quote either scoring, so give both. Describe it as a widely used 11-question fatigue questionnaire. It can show how much fatigue you report and how that changes; it cannot diagnose ME/CFS or long COVID. See preparing for a GP appointment.

Sources