NIHSS Stroke Scale Calculator
Score 11 neurological items from the NIH Stroke Scale to quantify stroke severity and support treatment decisions.
For educational use only. Valid NIHSS assessment requires a certified examiner following the standardized NIH protocol. Never use scores from this tool as the sole basis for treatment decisions.
1a Level of Consciousness
Score the response even if a full evaluation is not possible. A score of 3 is given only if the patient makes no movement.
1b LOC Questions
Ask the patient: "What month is it?" and "How old are you?" Score number of correct answers (first attempt only).
1c LOC Commands
Ask the patient to open and close eyes, then grip and release the non-paretic hand. Score number of tasks performed correctly.
2 Best Gaze
Test horizontal eye movements. Voluntary or reflexive (oculocephalic) movement is scored. Score only horizontal gaze.
3 Visual Fields
Test visual fields (upper and lower quadrants) by confrontation using finger counting or visual threat. Score bilateral visual loss as 3.
4 Facial Palsy
Ask the patient to show teeth, raise eyebrows, and close eyes. Score symmetry of grimace in response to noxious stimuli in poorly responsive patients.
5 Motor Arm — Left & Right
Extend arm 90° (if sitting) or 45° (if supine) for 10 seconds. Score each arm separately. Mark 9 = untestable (amputation or joint fusion).
Left Arm (5a)
Right Arm (5b)
6 Motor Leg — Left & Right
Hold leg at 30° (always supine) for 5 seconds. Score each leg separately.
Left Leg (6a)
Right Leg (6b)
7 Limb Ataxia
Finger-nose-finger and heel-shin tests. Score only if present out of proportion to weakness. Score 0 if patient cannot understand or is paralyzed.
8 Sensory
Test sensation using pinprick. Score sensory loss only when clearly demonstrated (not minor side-to-side asymmetry). Bilateral loss scores 2.
9 Best Language (Aphasia)
Name items on a picture card, describe a scene, and read sentences. Score based on comprehension and fluency across all responses.
10 Dysarthria
Ask patient to read or repeat words from a list. Score only slurring — do not score aphasia here. Score 9 if intubated or other physical barrier.
11 Extinction / Inattention (Neglect)
Sufficient information to identify neglect may be obtained during the prior testing. Score 0 if severe visual loss prevents double simultaneous stimulation.
Score each item on the left
and click Calculate.
NIHSS Total Score
Item Breakdown
Clinical Notes
NIHSS Score — Stroke Severity Reference
| NIHSS Score | Severity | Clinical Implications |
|---|---|---|
| 0 | No stroke symptoms | Normal examination |
| 1–4 | Minor stroke | May not meet tPA threshold; consider clinical context |
| 5–15 | Moderate stroke | Core tPA eligibility range; evaluate for thrombectomy |
| 16–20 | Moderate-to-severe | High hemorrhagic risk with tPA; LVO likely |
| 21–42 | Severe stroke | Thrombectomy priority; high risk of poor functional outcome |
Source: Brott T et al., Stroke 1989; Adams HP et al., Stroke 1994. tPA eligibility based on AHA/ASA 2019 guidelines — always consult current institutional protocols.
Summary
Score 11 neurological items from the NIH Stroke Scale to quantify stroke severity and support treatment decisions.
How it works
- Score each of the 11 NIHSS items using the defined ordinal scale for that item.
- Use the worst response observed for each item — never coach the patient.
- Enter 0 if the patient performs the task normally.
- Click Calculate to see the total NIHSS score and severity interpretation.
- Review the per-item point breakdown to identify the dominant deficit pattern.
- Serial assessments (e.g., at 24 h, day 7) allow tracking of neurological change.
Use cases
- Triage acute stroke patients and document baseline deficit severity.
- Assess IV tPA eligibility based on NIHSS range (typically 4–22).
- Guide referral for mechanical thrombectomy (NIHSS >= 6 with large-vessel occlusion).
- Communicate neurological status objectively during handover and family discussions.
- Track neurological improvement or deterioration with serial NIHSS measurements.
- Stratify patients for stroke clinical trial enrollment.
- Educate neurology residents and nurses on standardized neurological examination.
- Document deficits for rehabilitation planning and discharge disposition.