Glasgow Coma Scale (GCS) Calculator
Add the eye, verbal and motor responses into a Glasgow Coma Scale total from 3 to 15 and read the mild, moderate or severe impairment band.
How it works
GCS = Eye (1–4) + Verbal (1–5) + Motor (1–6) · 13–15 mild, 9–12 moderate, 3–8 severe
The Glasgow Coma Scale grades consciousness by scoring the best eye, verbal and motor responses, giving a total between 3 (deep coma) and 15 (fully alert). Reporting the three components separately (for example E3 V4 M5) is preferred to a single number because the same total can reflect very different clinical pictures, and the motor score carries the most prognostic weight. A GCS of 8 or below is the traditional threshold for concern about protecting the airway.
Worked example
A patient who opens their eyes to speech (E3), is confused (V4) and localises to pain (M5) scores 3 + 4 + 5 = 12 — the moderate-impairment band, reported as E3 V4 M5, GCS 12.
Frequently asked questions
Why is the lowest possible score 3, not 0?
Each of the three components has a minimum of 1, even in an unresponsive patient, so the floor is 1 + 1 + 1 = 3. There is no zero on the scale.
Why report the components, not just the total?
Two patients can share a total but differ sharply — for example a low motor score is more ominous than a low verbal score. Recording E, V and M separately preserves that detail.
What if the patient is intubated?
A verbal score cannot be assessed through an endotracheal tube, so clinicians note it as "T" and rely on the eye and motor components. This simple calculator assumes a testable verbal response.
Related calculators
Educational clinical estimate only — not a diagnosis, medical advice, or treatment. Scores are screening aids that must be interpreted by a qualified clinician alongside the full clinical picture. Never make care decisions from this tool alone.