NIH Stroke Scale (NIHSS) Calculator

The NIHSS is a standardized neurological exam that grades the severity of an acute stroke. It is organized as 11 clinical items (with bilateral motor items and three consciousness sub-items, 15 scored components in total) covering level of consciousness, gaze, visual fields, facial palsy, arm and leg motor strength, limb ataxia, sensation, language, dysarthria, and neglect. It was developed for the NINDS rt-PA stroke trials and is now used worldwide to track stroke severity and guide treatment.

Each of the 15 items is scored as a whole number, and the scores are added together. The total ranges from 0 (no measurable deficit) to 42 (the most severe presentation). Higher scores mean a more severe stroke. This calculator sums the items for you as you choose each value.

A common clinical convention reads the total like this: 0 means no stroke symptoms, 1 to 4 is a minor stroke, 5 to 15 is a moderate stroke, 16 to 20 is moderate to severe, and 21 to 42 is a severe stroke. These bands describe severity at one point in time, and a change in the score over time is often more informative than a single reading.

On the official NIH Stroke Scale form, some motor and limb items can be marked untestable (for example, an amputated or fused limb). An untestable item contributes 0 to the total, so set those items to 0 here. Score every other item from your bedside exam to keep the total accurate.

No. The NIHSS quantifies severity and helps weigh the risks and benefits of treatments such as thrombolysis or thrombectomy, but it is not a strict cutoff on its own. Treatment decisions depend on the full clinical picture, imaging, time from symptom onset, and other factors that a stroke team evaluates together.

No. This tool is for education and quick reference only and is not a substitute for professional medical advice, diagnosis, or treatment. NIHSS scoring should be performed by a trained clinician, and anyone with possible stroke symptoms needs emergency medical care right away.