Glasgow Coma Scale (GCS) Calculator
Free Glasgow Coma Scale calculator. Score eye, verbal and motor response for an instant GCS total out of 15 with severity (mild, moderate, severe).
Updated 2026-06-14 · Free · No sign-up · Runs privately in your browser
Show the breakdown
Educational tool only. The GCS is one part of a neurological assessment and is not a standalone diagnosis. Not medical advice.
How the Glasgow Coma Scale Calculator Works
The Glasgow Coma Scale (GCS) is the most widely used tool for describing a person’s level of consciousness, especially after a head injury, stroke or other neurological event. Select the best response observed in each of the three categories — eye opening, verbal response and motor response — and the calculator adds them into a total out of 15 with a severity band.
The Formula
GCS = Eye opening + Verbal response + Motor response
Each component has a fixed range, so the total runs from a minimum of 3 to a maximum of 15.
| Component | Range | Best response (max) | No response (min) |
|---|---|---|---|
| Eye opening (E) | 1–4 | Spontaneous (4) | None (1) |
| Verbal response (V) | 1–5 | Oriented (5) | None (1) |
| Motor response (M) | 1–6 | Obeys commands (6) | None (1) |
The full scale breaks down as follows:
| Score | Eye opening | Verbal | Motor |
|---|---|---|---|
| 6 | — | — | Obeys commands |
| 5 | — | Oriented | Localizes to pain |
| 4 | Spontaneous | Confused | Normal flexion |
| 3 | To speech | Inappropriate words | Abnormal flexion |
| 2 | To pressure | Incomprehensible sounds | Extension |
| 1 | None | None | None |
Worked Example
A patient opens their eyes to speech (E = 3), gives confused answers (V = 4) and obeys commands (M = 6):
- GCS = 3 + 4 + 6 = 13 / 15
A total of 13 falls in the mild range. Results are usually written out as the components too — here, E3 V4 M6.
Interpreting the Total
- 13–15: Mild — minor impairment of consciousness.
- 9–12: Moderate.
- 3–8: Severe — often associated with a reduced ability to protect the airway.
Recording the three component scores (for example, E3 V4 M6) is recommended alongside the total, because the same total can come from different combinations. A patient’s trend over time — improving or declining — is often more informative than any single reading.
What the Score Does and Does Not Tell You
The GCS is designed to give a fast, repeatable description of consciousness so that different clinicians can communicate clearly. It is not a complete neurological exam and does not, on its own, diagnose the cause of impairment. Factors such as sedation, intubation (which makes the verbal score untestable), intoxication and language barriers can affect scoring. This tool is educational; the actual score is assigned by trained clinicians and interpreted within the full clinical picture.
Frequently asked questions
What is the Glasgow Coma Scale?+
The Glasgow Coma Scale (GCS) is a standardized way to describe a person's level of consciousness after a brain injury. It scores three responses — eye opening, verbal response and motor response — and adds them to a total from 3 to 15. A higher score means a higher level of consciousness.
How is the GCS score calculated?+
Add the three components together: eye opening (1 to 4), best verbal response (1 to 5) and best motor response (1 to 6). The lowest possible total is 3 and the highest is 15. For example, eyes opening to speech (3), confused speech (4) and obeying commands (6) gives a GCS of 13.
What is a normal GCS score?+
A fully alert person scores 15 out of 15: eyes open spontaneously (4), oriented speech (5) and obeying commands (6). The minimum score is 3, which represents no response in any category. A score of 15 is considered normal.
What do mild, moderate and severe GCS mean?+
GCS is commonly grouped as severe (3 to 8), moderate (9 to 12) and mild (13 to 15). A score of 8 or below often indicates a need to protect the airway. The grouping helps communicate severity quickly, but clinical judgment and trends over time matter more than a single number.
What does GCS 3 mean?+
A GCS of 3 is the lowest possible score: no eye opening (1), no verbal response (1) and no motor response (1). It indicates deep unconsciousness or coma. Because the scale starts at 3, there is no GCS of 0, 1 or 2.