NIH Stroke Scale (NIHSS) Calculator
Score all 15 items of the validated NIH Stroke Scale — consciousness, gaze, vision, facial palsy, motor arms and legs, ataxia, sensory, language, dysarthria, and extinction — to get a total from 0 (no deficit) to 42 (most severe). Each domain is broken down separately.
1a. Level of Consciousness (LOC)
1b. LOC Questions (month / age)
1c. LOC Commands (open/close eyes, grip)
2. Best Gaze
3. Visual Fields
4. Facial Palsy
5a. Motor Arm — Left
5b. Motor Arm — Right
6a. Motor Leg — Left
6b. Motor Leg — Right
7. Limb Ataxia
8. Sensory
9. Best Language
10. Dysarthria
11. Extinction and Inattention
Score 0–42 • 0 = no deficit; higher scores indicate greater severity
- 1
Consciousness (1a + 1b + 1c)
0 - 2
Vision & gaze (2 + 3 + 4)
0 - 3
Motor arms & legs (5a + 5b + 6a + 6b)
0 - 4
Sensory, language & ataxia (7 + 8 + 9)
0 - 5
Dysarthria + extinction (10 + 11)
0 - 6
NIHSS total score
0 + 0 + 0 + 0 + 0 = 0
How does this calculator work?
NIHSS sums 15 items (consciousness, gaze, vision, facial palsy, 4 motor items, ataxia, sensory, language, dysarthria, extinction) for a total of 0–42. Score 0 = no deficit; 1–4 = minor; 5–15 = moderate; 16–20 = moderate–severe; 21–42 = severe. For clinical reference only — findings must be confirmed by a qualified clinician.
Formula
How this is calculated
The NIH Stroke Scale (NIHSS) is a standardised 15-item neurological examination developed by the National Institutes of Health to quantify stroke severity at presentation and to track change over time. Each item is scored by selecting the best response the patient demonstrates. Scores are summed to produce a total from 0 (no detectable deficit) to 42 (the highest possible impairment). The motor subscores (items 5a, 5b, 6a, 6b) run to 4, with 4 representing untestable limbs — all other items run to 2 or 3.
Severity thresholds are widely used in clinical practice and research: 0 = no deficit; 1–4 = minor stroke; 5–15 = moderate stroke; 16–20 = moderate-to-severe stroke; 21–42 = severe stroke. A score of 25 or above suggests a very large hemisphere infarct or brainstem/posterior circulation event. Eligibility for IV thrombolysis (tPA) and endovascular thrombectomy is partly guided by NIHSS scores, but the decision also depends on symptom onset time, imaging, contraindications, and local protocols.
The scale was designed to be administered by trained clinicians at the bedside. It assumes the examiner tests the best observed response, not the worst, and follows a fixed item order. Modifications such as the mNIHSS omit certain items. This calculator implements the standard 15-item version for educational and reference purposes; clinical decisions must be made by qualified practitioners using validated bedside assessment.
Frequently asked questions
A score of 0 indicates no detectable neurological deficit. Any score above 0 represents some degree of impairment. Scores of 1–4 are generally classified as minor strokes and are associated with better functional outcomes; scores of 5–15 indicate moderate strokes; 16–42 indicate moderate-to-severe or severe strokes with higher disability and mortality risk.
NIHSS score is one input into thrombolysis decisions: patients with very minor deficits (NIHSS 0–1) may not meet criteria, while very high scores may suggest poor prognosis or large infarct. However, eligibility also depends on symptom onset, CT/MRI findings, blood pressure, anticoagulation status, and local protocols. Always defer to current clinical guidelines and institutional criteria.
A motor score of 4 (UN) means the limb cannot be tested — for example due to pre-existing weakness, amputation, or fracture. It is counted as 4 in the total score for calculation purposes, but should be documented as "untestable" (UN) rather than 4 in formal recording, so reviewers know the deficit is not attributable to the acute stroke.
Also known as
TG we-Calculate Editorial Team. (2026). NIH Stroke Scale (NIHSS) Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/nih-stroke-calculator
TG we-Calculate Editorial Team. "NIH Stroke Scale (NIHSS) Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/nih-stroke-calculator.
TG we-Calculate Editorial Team, "NIH Stroke Scale (NIHSS) Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/nih-stroke-calculator
@misc{wecalculate_nih_stroke_calculator, title = {NIH Stroke Scale (NIHSS) Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/nih-stroke-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?