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 and where they are (5), and follows commands (6). Anything under 15 means something is off. Even a 14 should be watched closely.

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

There is an old saying: GCS 8, intubate . At a score of 8 or below, most people cannot cough, swallow, or keep their tongue out of the way. That puts them at risk of choking or breathing vomit into their lungs. A breathing tube protects the airway. But the number alone does not decide it. The care team also looks at breathing, gag reflex, oxygen levels, and whether the cause is likely to reverse fast, like low blood sugar or an opioid overdose.

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

Coma is usually a score of 8 or less . In simple terms, a person in a coma does not open their eyes, does not follow commands, and does not speak words. Scores of 3 to 8 are all labeled severe brain injury, but a 3 is much worse than an 8.

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

This is the most common scoring mistake. Localizing (6... actually 5 points): the hand moves toward the spot that hurts, crossing the midline or reaching above the collarbone to push it away. This is purposeful. Withdrawal (4 points): the arm just pulls away from the pain. It is a reflex-like jerk, not aiming. Reaching toward you scores higher than pulling back.

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 points
Verbal response (V), worth 1 to 5 points
Motor response (M), worth 1 to 6 points

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

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

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 and where they are (+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.

Clear All button: Click Clear All 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.

The Three Parts of the GCS

Eye opening (E), scored 1 to 4. Do the eyes open on their own, when spoken to, when hurt, or not at all?
Verbal response (V), scored 1 to 5. 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. 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. The highest is 15. A score of 15 means the person is fully awake and acting normally.

What the Score Means

13 to 15. Mild brain injury. The person is awake and mostly alert.
9 to 12. Moderate brain injury. The person is confused or drowsy and needs close watching.
3 to 8. Severe brain injury. The person is in a coma or close to it. Care teams often think about a breathing tube if the person cannot protect their airway.

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. You should not guess a number or give a 1. Instead, write the score as a scale, like E3 VNT M5. Adding up a partial score would make the patient look worse than they are.

How the GCS Is Used

The GCS was created in 1974 in Glasgow, Scotland, and is now used all over the world. Ambulance crews, emergency rooms, and intensive care units repeat the test often to see if a person is getting better or worse. A drop of 2 or more points is a warning sign and usually means the patient needs a scan or a doctor right away.

Good Things to Remember

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

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

\text{GCS} = E + V + M

Severity classification by total score

\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}

Sum of testable components (when any component is NT)

\text{Testable sum} = \sum_{i \in \{E,V,M\}} c_i \quad \text{for components } c_i \neq \text{NT}

Maximum possible points of testable components

\text{Testable max} = \sum_{i \in \{E,V,M\}} m_i, \quad m_E = 4,\; m_V = 5,\; m_M = 6

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 and where they are (5), and follows commands (6).

Anything under 15 means something is off. 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. Even a person with no response at all gets 1 for eyes, 1 for speech, and 1 for movement.

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?

There is an old saying: GCS 8, intubate. At a score of 8 or below, most people cannot cough, swallow, or keep their tongue out of the way. That puts them at risk of choking or breathing vomit into their lungs.

A breathing tube protects the airway. But the number alone does not decide it. The care team also looks at breathing, gag reflex, oxygen levels, and whether the cause is likely to reverse fast, like low blood sugar or an opioid overdose.

What GCS score means a person is in a coma?

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

Scores of 3 to 8 are all labeled severe brain injury, but a 3 is much worse than an 8.

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

This is the most common scoring mistake.

Localizing (6... actually 5 points): the hand moves toward the spot that hurts, crossing the midline or reaching above the collarbone to push it away. This is purposeful.
Withdrawal (4 points): the arm just pulls away from the pain. 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 bad signs of deep brain damage, but they score differently.

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

Decerebrate is worse. It points to damage lower in the brainstem. If a patient changes from bending to straightening, that is a warning sign of worsening pressure in the brain.

How do you apply a painful stimulus to test GCS?

Start with a loud voice and gentle shaking. If there is no response, use a central stimulus first:

Squeeze the trapezius muscle where the neck meets the shoulder
Press on the supraorbital notch (above the eyebrow). Skip this one if the face is hurt

Then check a limb with nail bed or finger pressure. Use central pain to judge eye opening and speech. 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.

Many hospitals also write a "T" after the total, like 8T, meaning the total does not include a real verbal score. Never give an automatic 1 for verbal. That makes the patient look sicker than they are.

How often should the GCS be checked?

It depends on how sick the person is. A common pattern after head injury is every 15 minutes for the first 2 hours, then every 30 minutes, then hourly once the score stays stable.

The trend matters more than one number. A drop of 2 or more points means call a doctor right away and think about a repeat CT scan.

What is the Pediatric Glasgow Coma Scale?

It is a version made for babies and young children who cannot talk or follow commands yet. The eye and motor parts stay about the same, but the verbal part is changed:

5: coos, babbles, smiles, follows objects
4: cries but can be comforted
3: cries and will not be comforted
2: moans or grunts to pain
1: no sound

It is generally used under age 2, and the total still runs 3 to 15.

Can alcohol or drugs lower a GCS score?

Yes. Alcohol, opioids, sedatives, low blood sugar, low oxygen, seizures, and infections can all drop the score without any brain bleed.

That is why a low score is never blamed on drinking alone. 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 a bleed inside the skull. Concussions often score 15.

Warning signs that still need a scan include vomiting, worsening headache, a seizure, memory loss around the event, blood thinners, older age, or a dangerous mechanism like a car crash or a fall from height.

What is the difference between GCS and AVPU?

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

It takes seconds and is good for a first look or for large numbers of patients. GCS gives far more detail and tracks small changes over time, so hospitals use GCS for ongoing checks. Roughly, "P" on AVPU lines up with a GCS around 8.

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 score of 3 to 8 do survive and recover, especially if the cause is treatable.

Doctors look at the whole picture: the motor score, pupil reaction, age, CT findings, and how the score changes over hours and days. The motor part is the strongest single predictor of the three.

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

Because the same total can mean very different things. A patient with E4 V4 M1 and one with E1 V1 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.