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Glasgow Coma Scale Calculator

Calculate the GCS score from eye, verbal, and motor responses. Get severity classification and clinical interpretation.

Quick Answer

The Glasgow Coma Scale (GCS) measures consciousness level on a scale of 3 to 15. It sums three components: Eye opening (1-4), Verbal response (1-5), and Motor response (1-6). A score of 15 is fully conscious. Scores of 13-15 indicate mild injury, 9-12 moderate injury, and 3-8 severe injury (coma). GCS of 8 or below typically requires intubation.

Eye Opening Response (E)

Verbal Response (V)

Motor Response (M)

Your Results

Total GCS

out of 15

Eye (E)

of 4

Verbal (V)

of 5

Motor (M)

of 6

Mild InjuryGCS 15/15 (E4V5M6)

Mild brain injury. Patient is likely conscious and oriented. Good prognosis in most cases.

GCS Severity Scale

Severe (3-8)

Moderate (9-12)

Mild (13-15)

381215

Important: The Glasgow Coma Scale is a clinical assessment tool that should be performed and interpreted by trained medical professionals. This calculator is for educational purposes only. In a medical emergency, call your local emergency number immediately. Do not delay seeking emergency care to use this tool.

About This Tool

The Glasgow Coma Scale (GCS) is the most widely used scoring system for assessing the level of consciousness in patients with acute brain injury. Developed in 1974 by Graham Teasdale and Bryan Jennett at the University of Glasgow, Scotland, the GCS was created to provide a standardized, reproducible method for clinicians to communicate about a patient's neurological status. Before the GCS, descriptions of consciousness were vague and inconsistent, using terms like “stuporous” or “semi-conscious” that different clinicians interpreted differently. The GCS replaced this subjective language with an objective numerical score that could be tracked over time.

How the GCS Works

The GCS evaluates three independent aspects of a patient's response to stimulation. The Eye opening component (E, scored 1-4) assesses arousal and brainstem function. The Verbal response component (V, scored 1-5) evaluates language function and cognitive processing. The Motor response component (M, scored 1-6) tests the highest level of motor function, which is considered the most informative single predictor of outcome. The three scores are summed to produce a total between 3 (deepest coma, no responses) and 15 (fully alert and oriented). Importantly, the individual component scores (expressed as E4V5M6, for example) carry more clinical information than the total alone.

Severity Classification

GCS scores are grouped into three severity levels. A score of 13 to 15 is classified as mild traumatic brain injury (TBI). These patients are typically alert and oriented, or at most slightly confused. Most mild TBIs, including the majority of concussions, fall into this category. A score of 9 to 12 indicates moderate TBI. These patients are lethargic or obtunded and may be able to follow simple commands but cannot sustain attention or carry on a coherent conversation. A score of 3 to 8 represents severe TBI, indicating coma. Patients with a GCS of 8 or below generally cannot protect their airway and require endotracheal intubation. The motor component is particularly important in severe injuries, as it correlates most strongly with long-term outcome.

Clinical Applications Beyond Trauma

While the GCS was originally designed for traumatic brain injury, it is now used in many other clinical contexts. Emergency departments use it to assess patients with stroke, meningitis, hepatic encephalopathy, drug overdose, and metabolic derangements. Intensive care units track GCS serially to monitor trends in neurological status. The GCS is also a component of several other scoring systems, including the Revised Trauma Score, APACHE II (used in ICU mortality prediction), and the Injury Severity Score. In pre-hospital care, paramedics and EMTs use the GCS to triage patients and determine the level of care required during transport.

Limitations and the GCS-P

The GCS has several recognized limitations. It cannot be fully assessed in intubated patients (verbal component is not testable), sedated patients, or those with facial or orbital injuries preventing eye opening. In these cases, the untestable component is recorded as “NT” (not testable) rather than scored as 1, to avoid artificially lowering the total. The GCS also does not assess pupil reactivity, which is an important predictor of outcome after brain injury. To address this, the GCS-Pupils (GCS-P) score was proposed, subtracting 0, 1, or 2 points from the GCS total based on pupil reactivity (both reactive = 0, one reactive = 1, neither reactive = 2), yielding a score from 1 to 15. Inter-rater reliability can also be an issue, particularly for the verbal component, highlighting the importance of training in GCS assessment.

When to Use the GCS

The GCS should be assessed as early as possible after injury or onset of altered consciousness, and then repeated at regular intervals to detect improvement or deterioration. In hospital settings, GCS is typically recorded every 1 to 4 hours depending on severity. A decline of 2 or more points from a previous GCS score is clinically significant and often triggers urgent re-evaluation, imaging, or surgical intervention. For laypersons, understanding the GCS can help communicate the severity of a loved one's condition when speaking with medical teams, though actual scoring should always be performed by trained clinicians.

Frequently Asked Questions

What is a normal Glasgow Coma Scale score?

A normal GCS score is 15, indicating the patient is fully alert, oriented, and follows commands. This means eyes open spontaneously (E4), the patient is oriented and converses normally (V5), and obeys motor commands (M6). Any score below 15 indicates some degree of impaired consciousness.

What GCS score indicates a coma?

A GCS score of 8 or below is generally considered to indicate coma. At this level, the patient does not open eyes to verbal commands, cannot produce recognizable words, and does not follow motor commands. A GCS of 8 or below is one of the criteria for endotracheal intubation in emergency medicine to protect the patient's airway.

Can the GCS predict recovery from brain injury?

The GCS, particularly the motor component, is one of the strongest early predictors of outcome after traumatic brain injury. A higher initial GCS generally correlates with better outcomes. However, GCS alone cannot predict individual outcomes with certainty. Other factors including age, pupil reactivity, CT scan findings, and the presence of secondary injuries all influence prognosis. Serial GCS assessments over time are more informative than a single score.

How is GCS scored in intubated patients?

In intubated patients, the verbal component cannot be assessed and is recorded as 'NT' (not testable) or sometimes as '1T' to indicate the tube. The total GCS is then reported with this caveat, for example 'GCS 10T' or 'E3VntM6.' It is important not to simply assign a verbal score of 1, as this would underestimate the patient's true level of consciousness.

Is the Glasgow Coma Scale used for children?

A modified version called the Pediatric Glasgow Coma Scale is used for infants and young children (typically under 2 years) who cannot speak or follow verbal commands. The eye and motor components are similar, but the verbal scale is modified to age-appropriate responses such as cooing, babbling, crying, and irritability. For older children who can speak, the standard adult GCS is used.

What is the difference between GCS and GCS-P?

GCS-P (Glasgow Coma Scale-Pupils) adds pupil reactivity to the standard GCS. The pupil reactivity score subtracts 0 (both reactive), 1 (one reactive), or 2 (neither reactive) from the GCS total. This gives a range of 1-15 and improves prognostic accuracy, especially for moderate and severe injuries. GCS-P is increasingly recommended in neurocritical care guidelines.

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