Glasgow Coma Scale Calculator
Calculate the Glasgow Coma Scale (GCS) score from eye, verbal, and motor responses for assessing consciousness level.
About this calculator
Developed by Graham Teasdale and Bryan Jennett at the University of Glasgow in 1974, the GCS scores three observable responses -- eye opening (1-4), verbal response (1-5), and motor response (1-6) -- and sums them into a total of 3 to 15. The three components are not scored on the same scale: eye opening tops out at 4, verbal response at 5, and motor response at 6, so a one-level change in motor response shifts the total more than a one-level change in eye opening. That asymmetry is intentional, not an error -- motor response has consistently shown the strongest correlation with outcome of the three components, which is why abbreviated tools like the simplified motor score use it alone as a fast proxy for the full GCS in prehospital settings.
A total of 13-15 is classified mild traumatic brain injury, 9-12 moderate, and 3-8 severe; a GCS of 8 or less is the traditional threshold at which airway protection (intubation) is typically considered, because patients at that level generally cannot protect their own airway. GCS is a snapshot, not a diagnosis -- it should be trended over time, and a single low reading in a sedated, paralyzed, or intubated patient (who cannot produce a verbal response at all) needs the same clinical context a raw number can't supply. This calculator reports the total along with each component so a clinician can see which domain -- eyes, speech, or movement -- is driving a low score.
Medical Disclaimer
This calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about your health. Never disregard professional medical advice or delay seeking it because of results from this tool.
Inputs
Results
Total GCS Score
15/ 15
Figures current as of 1974. Source: Teasdale G, Jennett B. Assessment of coma and impaired consciousness: a practical scale. Lancet. 1974;304(7872):81-84.
How to Use This Calculator
- Score Eye Opening Response (1–4), Verbal Response (1–5), and Motor Response (1–6).
- Review Total GCS Score (3–15) — 13–15 is mild, 9–12 is moderate, ≤ 8 is severe TBI.
- GCS ≤ 8 typically warrants airway protection.
What each input means
- Eye Opening Response
- Eye opening response per Glasgow Coma Scale (Teasdale & Jennett, 1974).
- Verbal Response
- Verbal response per GCS.
- Motor Response
- Motor response per GCS.
How this is calculated
Worked example, using the default values
- Identify Input ParametersEye Opening Response = 4, Verbal Response = 5, Motor Response = 6 = 3 input(s) provided
- Calculate Total GCS ScoreTotal GCS Score15 = 15
- Calculate Eye Component4 = 4
- Calculate Verbal Component5 = 5
Figures and sources
- Glasgow Coma Scale (15-point consciousness assessment) (1974) — Teasdale G, Jennett B. Assessment of coma and impaired consciousness: a practical scale. Lancet. 1974;304(7872):81-84.
Engine last updated . Checked against 2 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why does motor response affect the total GCS more than eye opening does?
Motor response is scored 1 to 6 while eye opening is scored only 1 to 4, so moving motor response through its full range shifts the total by up to 5 points compared to up to 3 points for eye opening. This isn't an arbitrary weighting -- motor response has repeatedly shown the strongest individual correlation with neurological outcome among the three GCS components, which is also why the motor score alone is used as a rapid prehospital triage shortcut when a full assessment isn't practical.
What GCS score typically prompts airway protection?
A total GCS of 8 or less is the classic threshold ("GCS less than 9, intubate") at which clinicians generally consider securing the airway, because patients scoring this low often cannot protect it themselves from aspiration. This calculator flags that threshold automatically as "Intubation Indicated," but the decision in practice also weighs trend, mechanism of injury, and other vital signs, not the GCS number in isolation.
Can the Glasgow Coma Scale be scored in an intubated patient?
Not fully -- an intubated patient cannot produce a verbal response, which is one of the scale's three original components. Many centers document this as "GCS-T" or substitute a "1T" for the verbal component, but the resulting total is not directly comparable to a score from a patient who can speak, so trends and documentation should note the limitation rather than treat every 15-point scale the same way.
Is a GCS of 15 the same regardless of which components produced it?
Only one combination reaches 15: spontaneous eye opening, oriented speech, and obeying commands. Because a 15 requires every component at its maximum, a full recount of the three sub-scores is still worth confirming rather than trusting the total alone, especially when serial exams are being compared to detect subtle deterioration.
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