NIH Stroke Scale (NIHSS) Calculator. Score stroke severity using the NIH Stroke Scale (NIHSS) Calculator. Enter assessments for 11 neurological domains — including level of consciousness, gaze, visual fields, facial palsy, motor arm/leg, limb ataxia, sensory, language, dysarthria, and extinction — and get your total NIHSS score with corresponding stroke severity classification. Also try the Gupta Risk Calculator (MICA).
The NIH Stroke Scale is a standardized neurological assessment tool used by clinicians to objectively quantify the impairment caused by a stroke. It evaluates 11 domains including consciousness, vision, motor function, sensation, language, and attention. Scores range from 0 (no deficit) to 42 (most severe). See also our CHADS2 Score Calculator.
A score of 0 indicates no stroke symptoms. Scores 1–4 suggest a minor stroke, 5–15 a moderate stroke, 16–20 a moderate-to-severe stroke, and 21–42 a severe stroke. Higher scores are associated with worse outcomes and greater infarct volume.
The NIHSS is designed to be administered by trained healthcare professionals, including physicians, nurses, and paramedics. While formal certification is recommended for research settings, clinicians can use it in routine practice after reviewing administration guidelines.
Yes. The NIHSS is one of several criteria considered when evaluating eligibility for IV thrombolysis (tPA). Patients with rapidly improving deficits (very low NIHSS) or very severe strokes (very high NIHSS) may require special consideration. Always follow your institution's stroke protocol.
'UN' is recorded for items that cannot be assessed due to physical barriers, such as amputation, joint fusion, or intubation. Untestable items do not contribute to the total score, and this calculator excludes those items from the sum accordingly.
The NIHSS is typically assessed at initial presentation, at 24 hours, at 7–10 days or discharge, and at 3 months. Serial assessments help track neurological improvement or deterioration and inform decisions about escalation of care.
The NIHSS is known to underestimate deficits in posterior circulation strokes, as it does not specifically assess cerebellar function, diplopia, vertigo, or dysconjugate gaze in detail. Clinicians should interpret scores cautiously in patients with brainstem or cerebellar involvement.
The maximum NIHSS score is 42, though in practice scores above 30 are rarely seen. A score of 42 would indicate severe impairment across all assessed domains. Scores above 25 generally indicate a very severe stroke with poor prognosis for functional independence. You might also find our calculate APACHE II Score useful.