GCS Calculator

Q: What is a normal GCS score?

A normal score is 15 . That means the person opens their eyes on their own (4), talks and knows who they are, where they are and the date (5), and follows commands (6). 2 In most people, anything under 15 means something is off. Some people, such as those with dementia, a long-term neurological condition or a learning disability, may have a usual score below 15. 5 Their score is compared with that usual level. 5 Even a 14 should be watched closely.

Q: Why is the lowest GCS score 3 and not 0?

Each of the three parts starts at 1 point, not 0. 1 Even a person with no response at all gets 1 for eyes, 1 for speech, and 1 for movement. 1 1 + 1 + 1 = 3. So 3 is the floor. A score of 0, 1, or 2 is not possible on the adult scale.

Q: What GCS score means a person is in a coma?

Coma is usually a score of 8 or less . 5 In simple terms, a person in a coma does not open their eyes, does not follow commands, and does not speak words. 5 Scores of 3 to 8 are all labeled severe brain injury. 1 Even so, a 3 is the lowest score and means deep coma. 7

Q: What is the difference between decorticate and decerebrate posturing?

Both are ominous signs after a head injury. 9 They score differently on the GCS. Decorticate (3 points): arms bend in toward the chest, hands curl near the heart. 1 Think "toward the core." Decerebrate (2 points): arms and legs straighten and stiffen. 1 Decerebrate is worse. After a head injury, only about 37% of people with decorticate posturing survive, and only about 10% with decerebrate posturing. 9 Decerebrate posturing usually comes from damage lower in the brain than decorticate posturing. 9 If a patient changes from bending to straightening, pressure on the brain may be moving down toward the brainstem. 9

Q: How do you apply a painful stimulus to test GCS?

Start with a spoken or shouted request. 2 If there is no response, press on a finger tip. This is the pressure used to judge eye opening. 2 If there is still no response, apply firm pressure at one of two central sites. 8 Squeeze the trapezius muscle where the neck meets the shoulder 2 Press on the supraorbital notch (above the eyebrow). 2 Pressure here can make an injury to the eye or inside the head worse. 8 Never poke the face when testing eye opening, since it can cause a grimace that closes the eyes.

Eye Opening Response (E)

Mark NT if local injury, edema, or patient is otherwise unable to be assessed for eye opening.

Verbal Response (V)

Mark NT if the patient is intubated or otherwise unable to produce verbal responses.

Motor Response (M)

Mark NT if the patient is under sedation, pharmacological paralysis, or otherwise unable to be assessed for motor response.

Introduction

The Glasgow Coma Scale (GCS) is a quick way to check how awake and aware a person is after a head injury or brain problem. Doctors, nurses, and paramedics use it every day. This GCS calculator adds up your three scores and tells you what they mean.

You score three things:

Eye opening (E), worth 1 to 4 points¹
Verbal response (V), worth 1 to 5 points¹
Motor response (M), worth 1 to 6 points¹

Add them together and you get a total from 3 to 15.¹ A score of 13 to 15 means mild brain injury.¹ A score of 9 to 12 means moderate.¹ A score of 3 to 8 means severe.¹ At 8 or less, the patient may need help protecting their airway.⁵

Sometimes you can't test a part. A patient may be intubated, sedated, or have swollen eyes. Pick NT (Not Testable) for that part.² When you do, the tool shows the score in scale form, like E3 VNT M5, instead of a total. A total score is not reported when a part is Not Testable.⁷

Tap one choice in each column. The calculator shows your total, the severity level, a step-by-step solution, and a chart comparing your points to the max. Use it as a support tool, not a replacement for clinical judgment.

How to use our Glasgow Coma Scale (GCS) Calculator

Pick one answer for each of the three parts of the GCS exam: eye opening, verbal response, and motor response. The calculator adds your picks and shows the total GCS score out of 15, the brain injury level (mild, moderate, or severe), and a step-by-step solution.

Eye Opening Response (E): Choose how the patient opens their eyes, from opening them on their own (+4) down to no eye opening (+1). Pick NT if swelling or an eye injury makes this part impossible to test.

Verbal Response (V): Choose how the patient talks, from knowing who they are, where they are and the date (+5) down to making no sound (+1). Pick NT if the patient is intubated and cannot speak.

Motor Response (M): Choose how the patient moves, from following commands (+6) down to no movement at all (+1). Pick NT if sedation or paralytic drugs stop you from testing movement.

Calculate button: Click Calculate to see the GCS score, the severity level, and the chart. The score updates on its own each time you change an answer.

Reset button: Click Reset to erase your picks and start a new patient assessment.

What Is the Glasgow Coma Scale (GCS)?

The Glasgow Coma Scale is a simple test doctors and nurses use to check how awake and aware a person is after a head injury, stroke, or other brain problem. It looks at three things: how the person opens their eyes, how they talk, and how they move. Each part gets a number of points. Add the three numbers together to get the GCS score.¹

The Three Parts of the GCS

Eye opening (E), scored 1 to 4.¹ Do the eyes open on their own, when spoken to, when hurt, or not at all?
Verbal response (V), scored 1 to 5.¹ Can the person answer clearly, talk but sound mixed up, say only random words, make sounds, or say nothing?
Motor response (M), scored 1 to 6.¹ Can the person follow commands, reach toward pain, pull away, bend or stiffen the arms, or not move at all?

The lowest possible score is 3.³ The highest is 15.³ A score of 15 means the person is fully awake and acting normally.¹

What the Score Means

13 to 15. Mild brain injury¹. A score under 15 is still checked every half hour until it gets back to 15.⁵
9 to 12. Moderate brain injury¹. For people 16 and over, a score of 12 or less on the first assessment in the emergency department calls for a CT head scan within 1 hour.⁵
3 to 8. Severe brain injury¹. The person is in a coma or close to it.⁵ Care teams often think about a breathing tube if the person cannot protect their airway.⁵

Why "NT" (Not Testable) Matters

Sometimes a part cannot be tested. Swollen eyes can block eye opening. A breathing tube stops speech. Sleep medicine or paralyzing drugs can stop movement. In those cases you mark NT.² You should not guess a number or give a 1.² Instead, write the score as a scale, like E3 VNT M5. Adding up a partial score would give a low total that makes the patient look more unwell than they are.⁷

How the GCS Is Used

The GCS was created in 1974 in Glasgow, Scotland, and is now used all over the world.³ Ambulance crews, emergency rooms, and intensive care units repeat the test often to see if a person is getting better or worse.⁴ Even a 1-point drop that lasts 30 minutes is a warning sign, and a doctor should reassess the patient urgently.⁵ A CT scan is often the next step.⁵

Good Things to Remember

Always record the three parts (E, V, M) separately, not just the total.⁵ Two people can both score 9 but be very different.
The best response counts.² If one arm follows commands and the other does not, score the better side.
Alcohol and drugs can lower the score without a brain injury.¹ So can low blood sugar and seizures.
Young children need the Pediatric GCS instead, since babies cannot talk or follow commands.⁵

This tool is for learning and quick reference. It does not replace a real exam by a trained health professional.

Formulas used

Total GCS score ¹

\text{GCS} = E + V + M

Severity classification by total score ¹

\text{Severity} = \begin{cases} \text{Mild}, & 13 \le \text{GCS} \le 15 \\ \text{Moderate}, & 9 \le \text{GCS} \le 12 \\ \text{Severe}, & 3 \le \text{GCS} \le 8 \end{cases}

Marker position on the 3-15 severity scale

\text{Position}\;(\%) = \frac{\text{GCS} - 3 + 0.5}{13} \times 100

Frequently asked questions

What is a normal GCS score?

A normal score is 15. That means the person opens their eyes on their own (4), talks and knows who they are, where they are and the date (5), and follows commands (6).²

In most people, anything under 15 means something is off. Some people, such as those with dementia, a long-term neurological condition or a learning disability, may have a usual score below 15.⁵ Their score is compared with that usual level.⁵ Even a 14 should be watched closely.

Why is the lowest GCS score 3 and not 0?

Each of the three parts starts at 1 point, not 0.¹ Even a person with no response at all gets 1 for eyes, 1 for speech, and 1 for movement.¹

1 + 1 + 1 = 3. So 3 is the floor. A score of 0, 1, or 2 is not possible on the adult scale.

Why do doctors intubate a patient with a GCS of 8 or less?

UK head injury guidance calls for a breathing tube right away in coma, which it defines as a GCS of 8 or less.⁵ At a score of 8 or less, the gag reflex is unlikely to be normal.¹¹ Keeping the airway open and stopping vomit from getting into the lungs are top priorities in any badly ill or injured patient.¹¹

A breathing tube protects the airway. Coma is one reason for it. The same guidance also calls for one when the airway's protective reflexes are lost, when blood gases show too little oxygen or too much carbon dioxide, or when breathing is irregular.⁵

What GCS score means a person is in a coma?

Coma is usually a score of 8 or less.⁵ In simple terms, a person in a coma does not open their eyes, does not follow commands, and does not speak words.⁵

Scores of 3 to 8 are all labeled severe brain injury.¹ Even so, a 3 is the lowest score and means deep coma.⁷

What is the difference between localizing pain and withdrawal from pain?

The motor part is the hardest to score, especially telling a reach toward the pain apart from a pull away from it.⁸

Localizing (5 points): the hand moves toward the spot that hurts, reaching above the collarbone to push it away.² After pressure on a nail bed, the other hand may cross the midline to push it away.⁸ This is purposeful.
Withdrawal (4 points): the arm just pulls away from the pain.¹ It is a reflex-like jerk, not aiming.

Reaching toward you scores higher than pulling back.

What is the difference between decorticate and decerebrate posturing?

Both are ominous signs after a head injury.⁹ They score differently on the GCS.

Decorticate (3 points): arms bend in toward the chest, hands curl near the heart.¹ Think "toward the core."
Decerebrate (2 points): arms and legs straighten and stiffen.¹

Decerebrate is worse. After a head injury, only about 37% of people with decorticate posturing survive, and only about 10% with decerebrate posturing.⁹ Decerebrate posturing usually comes from damage lower in the brain than decorticate posturing.⁹ If a patient changes from bending to straightening, pressure on the brain may be moving down toward the brainstem.⁹

How do you apply a painful stimulus to test GCS?

Start with a spoken or shouted request.² If there is no response, press on a finger tip. This is the pressure used to judge eye opening.² If there is still no response, apply firm pressure at one of two central sites.⁸

Squeeze the trapezius muscle where the neck meets the shoulder²
Press on the supraorbital notch (above the eyebrow).² Pressure here can make an injury to the eye or inside the head worse.⁸

Never poke the face when testing eye opening, since it can cause a grimace that closes the eyes.

How is GCS scored for an intubated patient?

An intubated patient cannot speak, so the verbal part cannot be tested. The right way is to mark it NT and write the score as a scale, like E3 VNT M5.²

Some charts add the letters ET to the verbal part to show that the patient has a breathing tube.⁸ Do not report a total score when a part is Not Testable, because the total will be low and could confuse other staff.⁷ Never give an automatic 1 for verbal.² That makes the patient look sicker than they are.

How often should the GCS be checked?

It depends on how sick the person is. UK head injury guidance checks every 30 minutes until the score reaches 15.⁵ After that, the minimum is every 30 minutes for 2 hours, then hourly for 4 hours, then every 2 hours.⁵

The trend matters more than one number. A drop of even 1 point that lasts 30 minutes means a doctor should reassess the patient urgently and consider a CT scan.⁵

What is the Pediatric Glasgow Coma Scale?

It is a version for babies and young children, who cannot yet answer in an oriented way or obey commands. The Paediatric Glasgow Coma Scale described in Adelaide grades the best verbal response as talks normally, words, vocal sounds, cries, or none.⁷

The adult scale can be used without changes in children over 5 years old.⁷ A younger child's expected normal total rises with age, because a baby is not yet able to give the higher responses.

Can alcohol or drugs lower a GCS score?

Yes. Alcohol, sedatives and other drugs, seizures and low oxygen can all give a falsely low score.⁸ So can low blood sugar and infections.

That is why a low score is never blamed on drinking alone.⁵ A trauma patient with a low score gets scanned and treated as if the brain is injured until proven otherwise.

Does a GCS of 15 mean there is no brain injury?

No. A person can score 15 and still have an injury that shows on a CT scan. In a large UK study of children admitted to hospital with a head injury, an estimated 1 in 5 to 10 of the children with no impaired consciousness who had a CT scan had an abnormality on it.¹⁰

For people 16 and over, UK guidance calls for a CT scan within 1 hour for more than 1 episode of vomiting or a seizure after the injury.⁵ After any loss of consciousness or memory loss, a scan within 8 hours is advised for people 65 or over, people with a bleeding or clotting disorder, more than 30 minutes of memory loss for events just before the injury, and dangerous injuries such as a pedestrian or cyclist hit by a car or a fall from more than 1 metre or 5 stairs.⁵ Someone in that group who arrives more than 8 hours after the injury is scanned within the hour.⁵ For children under 16, a seizure after the injury calls for a scan within 1 hour.⁵ Signs such as 3 or more episodes of vomiting, being knocked out for more than 5 minutes or a fall from more than 3 metres call for a scan within 1 hour when more than 1 of them is present.⁵ With only 1 of them, the child is watched for at least 4 hours.⁵ A scan is also considered for people on blood thinners, except for those on aspirin alone.⁵ Severe or increasing headache during observation calls for urgent review.⁵

What is the difference between GCS and AVPU?

AVPU is a simpler, rougher check: Alert, responds to Voice, responds to Pain, or Unresponsive.¹⁰

It needs no formal training and is easy to use at the scene of an injury.¹⁰ GCS gives far more detail, and AVPU is not precise enough to closely track a patient who is getting worse.¹⁰ In two studies, people who responded only to pain had a median GCS of 8, but across studies the scores for this group spread widely.¹⁰

Does a low GCS score mean the person will not recover?

Not by itself. A low score early on is linked to worse outcomes, but many people with a low score survive. Even at a total of 4, the expected death rate is 19% or 48% depending on which parts make up the score.⁸

Doctors look at the whole picture: the score together with pupil reaction, age and CT findings.⁸ In severe injuries, the motor part predicts outcome best of the three.⁶

Why should you record E, V, and M separately instead of just the total?

Because the same total can mean very different things.⁴ A patient with E4 V4 M1 and one with E1 V2 M6 both total 9, but the second one can follow commands and the first one cannot move.

The three parts show exactly what changed between checks. Always chart the breakdown, such as E3 V4 M5 = 12.

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