How is the Glasgow coma scale calculated?

Add the best eye response (1 to 4), the best verbal response (1 to 5) and the best motor response (1 to 6), giving a total from 3 to 15. Always report the three parts as well as the total, for example E2 V3 M5 = 10, because the same total can mean very different patients.

What GCS is a severe head injury?

A GCS of 13 to 15 is a mild head injury, 9 to 12 moderate and 8 or less severe. A GCS of 8 or less usually means the patient cannot protect the airway and needs a definitive airway: hence the saying "GCS 8, intubate".

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Glasgow coma scale calculator

Creator: Dr. Mohammed Maree
Published: 2026-11-05
License: https://creativecommons.org/licenses/by-nc/4.0/

GCS and GCS-Pupils (GCS-P), using the updated 2014 terms.

Score the eyes, words and movements: what is this patient’s level of consciousness?

Written and clinically reviewed by Dr. Mohammed Maree, consultant minimally invasive and bariatric surgeon, Al-Makassed Hospital, Jerusalem, and Assistant Professor of Surgery, Al-Quds University. Last updated 5 November 2026.

The scale

Score	Eyes (E)	Verbal (V)	Motor (M)
6			Obeys commands
5		Orientated	Localising to pain
4	Spontaneous	Confused	Normal flexion (withdraws)
3	To sound	Words	Abnormal flexion (decorticate)
2	To pressure	Sounds	Extension (decerebrate)
1	None	None	None

Total 3 to 15. Mild 13–15, moderate 9–12, severe 8 or less.

How to apply the stimulus

Start with no stimulus, then speak, then apply pressure. The 2014 guidance recommends fingertip pressure (to the nail bed), trapezius pinch or supraorbital notch pressure for 10 seconds. Use a central stimulus (trapezius or supraorbital) to test for localising: the patient brings a hand above the clavicle towards the stimulus.

A worked example

A motorcyclist opens his eyes only when you press on his fingertip (E2), makes groans but no words (V2), and pulls his arm away from the pressure (M4). GCS 8: E2 V2 M4. Severe head injury: secure the airway, avoid hypoxia and hypotension, and arrange an immediate CT head and neurosurgical opinion.

Common mistakes

Report the best response, and always give the three parts, not only the total. Do not score the verbal response in an intubated patient: write V_T. The lowest possible score is 3, not 0. Sedation, alcohol, hypoglycaemia and hypotension all lower the score, so correct what you can and score again.

References

Teasdale G, Jennett B. Assessment of coma and impaired consciousness: a practical scale. Lancet 1974;2:81–4.
Teasdale G, et al. The Glasgow Coma Scale at 40 years: standing the test of time. Lancet Neurol 2014;13:844–54.
Brennan PM, Murray GD, Teasdale GM. Simplifying the use of prognostic information in traumatic brain injury: the GCS-Pupils score. J Neurosurg 2018;128:1612–20.
NICE NG232. Head injury: assessment and early management. 2023.
American College of Surgeons. ATLS: Advanced Trauma Life Support, 10th edition. 2018.

Educational use

This calculator is a teaching aid. It does not replace clinical judgement, senior advice or your local guidelines.

MCQsTrauma surgery questionsTest yourself on trauma.MCQsNeurosurgery questionsHead injury and raised pressure.ClerkingBlunt abdominal traumaA model trauma clerking.All toolsClinical calculatorsEvery calculator on the site.

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