Post-operative patient, slight change in behaviour noted on handover. You need a documented baseline GCS before the neurologist arrives.
Glasgow Coma Scale (GCS)
Assessment
GCS = Eye (1–4) + Verbal (1–5) + Motor (1–6)
Severity classification:15 = Normal · 13–14 = Minor · 9–12 = Moderate · ≤8 = Severe (airway risk)
💡 GCS ≤8 — "patient is not great" — intubation threshold. Always escalate immediately and document time of assessment.
Clinical safety:
🇦🇺 Verify with facility drug formulary and senior clinician · Meets AHPRA/ACSQHC standards
1 What this calculator does
Calculates the total Glasgow Coma Scale score from the three components — Eye opening (E), Verbal response (V) and Motor response (M). Classifies severity and flags the critical threshold of 8 or below.
2 Formula & professional reasoning
GCS Total = Eye (1–4) + Verbal (1–5) + Motor (1–6) | Range: 3–15
The GCS was developed by Teasdale and Jennett (1974) as a standardised way to assess conscious level. Each component scores independently — motor response is the strongest predictor of outcome. A total of ≤8 indicates severe brain injury and is the widely-used threshold for airway intervention.
3 Worked examples
⚠️ Illustrative example only — not clinical or professional instruction.
Basic
Alert patient
Given: E4 (spontaneous) · V5 (oriented) · M6 (obeys commands)
Working:
4 + 5 + 6 = 15Answer: GCS 15 — Normal
💡 Document as E4V5M6 in the notes, not just the total.
Standard
Post-ictal patient
Given: E3 (to voice) · V3 (words only) · M5 (localises)
Working:
3 + 3 + 5 = 11Answer: GCS 11 — Moderate
💡 Reassess every 15 minutes. Any downward trend needs escalation.
Advanced
Severe TBI
Given: E2 (to pressure) · V1 (none) · M3 (abnormal flexion)
Working:
2 + 1 + 3 = 6Answer: GCS 6 — Severe ⚠️
💡 GCS ≤8 — intubation threshold. Escalate immediately. Airway management priority.
4 Sanity check
GCS 15
Normal consciousness
Still document — baseline is critical for trend monitoring.
GCS 13–14
Minor injury
Close neurological observation. Reassess frequently.
GCS 9–12
Moderate impairment
Urgent medical review required.
GCS ≤8
Severe — protect airway
Intubation threshold. MET/RRT activation. Continuous monitoring.
5 Common errors
| Error | Cause | Consequence | Fix |
|---|---|---|---|
| Recording total only | Skipping component documentation | Trend changes missed — E2V2M4 vs E4V2M2 both = 8 but very different | Always document as E_V_M_ not just the total |
| Applying 'NT' (not testable) | Patient intubated or aphasic | Score underestimated without noting reason | Document as E_VTM_ where T = intubated; use 1T for verbal component |
| Scoring best response incorrectly | Assessing average not best | Artificially low score | Always score the BEST response observed — use painful stimulus if needed |
| Confusing flexion types | Normal vs abnormal flexion look similar | M4 vs M3 distinction missed — critical difference | Normal flexion = withdrawal with wrist flexion; abnormal = stereotyped decorticate posture |
6 Reference & regulatory links
7 Professional workflow
Common tools used alongside this one: