Glasgow Coma Scale (GCS) Calculator

Background.

The Glasgow Coma Scale grades impaired consciousness on three independent axes — eye opening, verbal response and best motor response — and reports them both separately and as a total from 3 to 15. This calculator is a clinical aid for clinicians. It does not diagnose anything, it does not predict outcome, and the number it produces is only as good as the examination behind it.

The most important habit the scale asks for is to report the components, not just the sum. A GCS of 10 can be E4 V1 M5 or E1 V3 M6, and those are different patients with different problems. The Glasgow group's own guidance is to record the three ratings; the total is a convenience for triage and communication, not the assessment itself. This page therefore prints the E-V-M summary alongside the total and treats it as a first-class output.

The wording used here is taken directly from the current Glasgow Coma Scale assessment aid published by the Institute of Neurological Sciences at NHS Greater Glasgow and Clyde and copyrighted to Sir Graham Teasdale in 2015. That matters because the terminology has changed and most reproductions have not kept up. The eye axis is now "to sound" — after a spoken or shouted request — and "to pressure" — after finger-tip stimulus. The older "to speech" and "to pain" describe the same observations but are no longer the published wording. Motor grade 5, localising, has a concrete definition: the hand comes above the clavicle in response to a stimulus on the head or neck. Motor grade 6 means obeying a two-part request, not a single reflexive squeeze.

There is a rule this calculator cannot honour by producing a number, so it states it in words instead. When a component cannot be tested — eyes swollen shut, an intubated patient who cannot speak, a paralysed limb — the correct practice is to record that component as NT and not to report a total at all. An intubated patient's verbal component is conventionally recorded as V-ET. If you are in that situation, do not use the total on this page; record the components you could test and mark the rest non-testable.

The history is usually told wrongly, and the correction is worth having. The 1974 Lancet paper by Teasdale and Jennett described the three axes but did not assign numbers to them. The first numbered version totalled 14 and had five motor grades. The sixth motor grade — separating normal flexion, or withdrawal, from abnormal flexion — is what raised the maximum to 15, and sources date that change to 1976 or to 1977. So "the 1974 3-to-15 scale" is not a thing that existed. What this calculator implements is the current 15-point scale exactly as the 2015 assessment aid publishes it.

The severity bands need their own caveat, which is why it sits beside the result rather than in a footnote. Severe 3 to 8, moderate 9 to 12 and mild 13 to 15 is the conventional classification of traumatic brain injury. It is not a general classification of impaired consciousness from any cause: a GCS of 7 from hypoglycaemia, opioid toxicity or the post-ictal state does not mean severe brain injury, and treating the band as a diagnosis in those settings is a category error. The paediatric picture differs too — a threshold of 5 rather than 8 has been reported to identify severe injury more accurately in children, and paediatric versions of the scale use different verbal criteria altogether.

One last arithmetic point that catches people: the floor is 3, not 0. Every axis has a minimum grade of 1, awarded for no response in a patient with no interfering factor, so a living patient cannot score below 3. A recorded GCS of 0, 1 or 2 is an error in transcription or in understanding, and this calculator rejects those values rather than quietly accepting them.

What is glasgow coma scale calculator?

The Glasgow Coma Scale is a structured assessment of consciousness built on three observations: whether and when the eyes open, the best verbal response, and the best motor response. Each is graded on an ordinal scale — eye opening from 1 to 4, verbal from 1 to 5, motor from 1 to 6 — and the three grades are reported individually and, where appropriate, as a sum from 3 to 15.

It was devised by Graham Teasdale and Bryan Jennett in Glasgow and first published in the Lancet in 1974 as a way of describing impaired consciousness reproducibly, replacing vague terms like "stuporose" and "semi-comatose" that different observers used differently. Numerical scoring came afterwards, and the six-grade motor axis that gives the familiar maximum of 15 was introduced a few years later.

In practice it is used to communicate a patient's neurological state between clinicians, to trigger escalation thresholds — a GCS of 8 or less has long been associated with the need to consider definitive airway management — and to track change over time, which is the use it is best at. A falling GCS is often more informative than any single value.

What it is not: a measure of brain injury severity outside trauma, a prognostic score on its own, a substitute for pupil assessment and a focused neurological examination, or something to be reported as a total when one of its components could not be tested.

How to use this calculator.

1. 01Check first for factors that interfere with assessment — sedation, paralysis, intubation, periorbital swelling, language barrier, hearing loss. If any component is genuinely non-testable, do not use a total.
2. 02Grade eye opening on the highest response observed: 4 if the eyes are open before any stimulus, 3 after a spoken or shouted request, 2 after finger-tip pressure, 1 for no opening at any time.
3. 03Grade the verbal response: 5 if the patient correctly gives name, place and date; 4 if communication is coherent but not orientated; 3 for intelligible single words; 2 for moans or groans only; 1 for no audible response.
4. 04Grade the best motor response in the best-responding limb: 6 for obeying a two-part request, 5 if the hand comes above the clavicle to a stimulus on the head or neck, 4 for rapid flexion at the elbow without abnormal features, 3 for clearly abnormal flexion, 2 for extension at the elbow, 1 for no movement.
5. 05Enter the three grades. The calculator reports the total, the E-V-M summary and the traumatic brain injury severity band.
6. 06Record and hand over the E-V-M summary, not only the total — the components carry the information the total discards.
7. 07Repeat the assessment. Change over time is what the scale is best at describing, and a single value never tells the whole story.
8. 08Do not read the severity band as a diagnosis when the cause is metabolic, toxic or post-ictal, and do not apply the adult thresholds to a child.

The formula.

The Glasgow Coma Scale total is the sum of three ordinal grades: eye opening from 1 to 4, verbal response from 1 to 5, and best motor response from 1 to 6. The minimum possible total is 1 + 1 + 1 = 3 and the maximum is 4 + 5 + 6 = 15. There is no grade of zero on any axis, so a total below 3 cannot occur.

Rounding stage: there is none, and no fractional score exists on the scale. Each axis takes a whole-number grade and the total is their exact integer sum. This calculator rejects a non-integer grade rather than rounding it, because rounding 12.5 either way would move a patient between the moderate and mild bands — a silent change of clinical category made by an implementation detail.

The grades themselves come from the 2015 Glasgow Coma Scale assessment aid. Eye opening: 4 spontaneous, meaning open before stimulus; 3 to sound, after a spoken or shouted request; 2 to pressure, after finger-tip stimulus; 1 none, with no interfering factor. Verbal: 5 orientated, correctly giving name, place and date; 4 confused, communicating coherently but not orientated; 3 words, intelligible single words; 2 sounds, only moans or groans; 1 none. Best motor: 6 obeys a two-part request; 5 localising, bringing the hand above the clavicle to a stimulus on the head or neck; 4 normal flexion, bending rapidly at the elbow without predominantly abnormal features; 3 abnormal flexion; 2 extension at the elbow; 1 none.

Each axis is scored on the best response observed, and the motor axis on the best-responding limb. That is a deliberate feature: the scale describes the best the nervous system can currently do, not the average of what it does.

Banding uses the conventional traumatic brain injury classification: 3 to 8 severe, 9 to 12 moderate, 13 to 15 mild. Those cuts are applied to the exact integer total, so 8 is severe and 9 is moderate, 12 is moderate and 13 is mild, with nothing in between.

Worked through the example on this page: eye opening to sound scores 3, a confused but coherent verbal response scores 4, and localising to a trapezius stimulus scores 5. The total is 3 + 4 + 5 = 12, the component summary is E3 V4 M5, and 12 falls in the moderate band. One additional point on any single axis would take the total to 13 and reclassify the patient as mild — which is precisely why the components are reported alongside the number.

A worked example.

Frequently asked questions.

References& sources.

1. [1]Glasgow Coma Scale Assessment Aid. Institute of Neurological Sciences, NHS Greater Glasgow and Clyde. © Sir Graham Teasdale 2015. Source of every criterion, rating and score implemented here, extracted verbatim from the official PDF — including the current "to sound" and "to pressure" wording and the localising definition (hand above the clavicle to a stimulus on head or neck). (Retrieved 2026-07-29.)
2. [2]Teasdale G, Jennett B. Assessment of coma and impaired consciousness. A practical scale. Lancet. 1974;2(7872):81–84. The original description of the three-axis scale. Cited to establish that the 1974 paper did not assign numerical scores. (Bibliographic; consulted 2026-07-29.)
3. [3]Teasdale G, Jennett B. Assessment and prognosis of coma after head injury. Acta Neurochirurgica. 1976;34(1–4):45–55. The expansion of the motor axis to six grades, giving the 15-point maximum. Sources date this change to 1976 or 1977; both are noted on the page rather than one being asserted. (Bibliographic; consulted 2026-07-29.)
4. [4]Glasgow Coma Scale. StatPearls, NCBI Bookshelf NBK513298. Source of the traumatic brain injury severity bands (severe 3–8, moderate 9–12, mild 13–15), the paediatric threshold caveat, and the verbatim rule: "Clinicians should denote any untestable component of the GCS as 'NT' (not testable) and avoid using the total score when a component is not testable." (Full text retrieved 2026-07-29.)
5. [5]The Glasgow structured approach to assessment of the Glasgow Coma Scale — glasgowcomascale.org, Institute of Neurological Sciences, NHS Greater Glasgow and Clyde. The issuing body's standing guidance on structured assessment and on reporting components rather than a bare total. (Consulted 2026-07-29.)