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Free Glasgow Coma Scale (GCS) Calculator (2026)
The Glasgow Coma Scale (GCS) is a 15-point neurological scale that describes a patient’s level of consciousness from three independently scored components: eye opening, verbal response, and motor response. Introduced in 1974 and still the standard bedside tool in emergency medicine, trauma, neurology, and critical care, GCS produces a total score from 3 (the lowest score obtainable) to 15 (fully alert and oriented), conventionally documented together with its three parts, for example “GCS 7 (E2V2M3).” The total is used to classify injury as mild, moderate, or severe, to track a patient’s neurological trajectory over time, and to help decide when airway protection or escalation of care is needed — a total of 8 or below is the threshold most trauma and airway-management protocols use to prompt consideration of intubation. The calculator below scores each component separately and reports the summed total and severity band. It is built for emergency physicians, trauma teams, neurologists, intensivists, and trainees who need a fast, standardized, and citable consciousness assessment. Select the best observed response in each component below to calculate a patient’s GCS instantly.
Clinical decision-support aid, not a substitute for clinical judgment. These tools implement published scoring criteria for education and workflow support. They are not a medical device and have not been reviewed by the FDA or any regulatory body. Every result should be interpreted by a qualified clinician in the context of the full clinical picture, not used as a standalone diagnostic or treatment decision.
Level of consciousness
GCS
Select the best observed response in each of the three components. The total (E+V+M) ranges from 3 to 15.
Teasdale G, Jennett B. Lancet. 1974;2(7872):81–84 · Teasdale G, Maas A, Lecky F, et al. Lancet Neurol. 2014;13(8):844–854.
A fully worked example
Consider a trauma patient who opens their eyes only to a painful stimulus (Eye = 2), makes incomprehensible sounds with no recognizable words (Verbal = 2), and shows abnormal flexion — decorticate posturing — to pain (Motor = 3). Summing the three components gives a GCS of 2 + 2 + 3 = 7 out of 15, documented as GCS 7 (E2V2M3). A total of 7 falls in the severe range (GCS 8 or below), the classic threshold many trauma and airway-management protocols use as a trigger to consider intubation for airway protection, independent of any single component. Recording the total together with its three components — rather than the number alone — preserves the clinically important detail of which component is driving the score. These same three responses are already loaded as the calculator’s defaults above.
Methods, assumptions, and when not to use GCS
For a manuscript methods section, GCS can be cited in a single sentence: “Level of consciousness was assessed using the Glasgow Coma Scale, scored as the sum of eye-opening (1-4), verbal (1-5), and motor (1-6) responses, range 3-15 (Teasdale & Jennett, Lancet 1974; Teasdale et al., Lancet Neurology 2014).” Because GCS is a fixed, published scale rather than a fitted or site-specific model, citing its original description and the 2014 structured-scoring update is sufficient methodological documentation.
The verbal component cannot be meaningfully scored in intubated, tracheostomized, or otherwise non-verbal patients; convention is to record this as GCS-T (appending a T to the total) and rely on the eye and motor components, rather than assigning an arbitrary verbal score. GCS is also less reliable in patients with baseline dementia or another chronic cognitive impairment, a language barrier or aphasia, sedation, neuromuscular blockade, or acute intoxication, since each of these can lower the apparent score for reasons unrelated to the acute process being assessed. GCS is best treated as one structured, reproducible data point in a fuller neurological and clinical assessment, not a freestanding diagnosis.
What do the E, V, and M components of GCS measure?
Eye opening (E, scored 1–4) ranges from spontaneous eye opening (4) through opening to speech or command (3) and opening only to a painful stimulus (2), down to no eye opening (1). Verbal response (V, scored 1–5) ranges from oriented, appropriate speech (5) through confused conversation (4), inappropriate words (3), and incomprehensible sounds (2), down to no verbal response (1). Motor response (M, scored 1–6) ranges from obeying commands (6) through localizing to pain (5), normal withdrawal from pain (4), abnormal flexion or decorticate posturing (3), and abnormal extension or decerebrate posturing (2), down to no motor response (1). The three are summed for the total, but each is also clinically meaningful on its own — motor response in particular carries much of the prognostic weight.
What GCS score indicates a severe brain injury?
A total GCS of 8 or below is conventionally classified as severe and is the threshold most widely used in trauma and airway-management protocols to prompt consideration of intubation for airway protection. A score of 9–12 is classified as moderate, and 13–15 as mild. These bands are useful for triage and communication, but the trend over serial assessments and the individual component scores often matter as much as a single total.
Can GCS be used in children?
The scale described here applies from roughly the school-age years onward. Infants and younger children, who cannot yet follow verbal commands or produce oriented speech, are assessed instead with a separate Pediatric Glasgow Coma Scale that substitutes age-appropriate verbal and motor criteria; the standard scale on this page is not intended for infants or very young children.
Primary references
Teasdale G, Jennett B. Assessment of coma and impaired consciousness: a practical scale. Lancet. 1974;2(7872):81–84.
Teasdale G, Maas A, Lecky F, et al. The Glasgow Coma Scale at 40 years: standing the test of time. Lancet Neurol. 2014;13(8):844–854.
Running a trauma-outcomes registry study?
GCS is one of the most heavily used variables in trauma registries, and building a publication-ready cohort around it takes careful registry-level cohort design and statistical analysis. Editverse’s NTDB/TQP Trauma Registry Study service handles registry access, cohort definition, risk-adjusted modelling, and a publication-ready manuscript. See the registry study service