For healthcare professionals
Shock index calculator
The shock index is the heart rate divided by the systolic blood pressure. In a study of 21,853 adult trauma patients, a higher shock index went with more blood transfusion and higher mortality. This calculator is written for clinicians and is not a diagnosis.
Vital signs
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What you will see
The shock index, its trauma shock group, and the mortality published for that group.
Educational only, not medical advice. Not a diagnosis. Treatment decisions belong to the treating team.
Source
Mutschler M and colleagues, Critical Care 2013 (open access, CC BY 2.0): the formula, the four shock groups and their outcomes. The normal range is from Middleton and colleagues, Journal of Clinical Medicine 2019 (CC BY 4.0). The tests check the formula and every group edge.
Validated in
21,853 adult trauma patients in the German TraumaRegister DGU from 2002 to 2011, with the shock index taken at emergency department arrival (Mutschler 2013). A systematic review also studied it in adults with sepsis or community-acquired pneumonia (Middleton 2019).
Limits
The groups and mortality figures come from trauma patients and may not apply to other settings. Prehospital care such as intravenous fluid can change the vital signs on arrival (Mutschler 2013). In sepsis the shock index was only a moderately accurate predictor of mortality (Middleton 2019).
Formula
Shock index = heart rate / systolic blood pressure (Mutschler 2013).
Worked example: heart rate 120 beats per minute and systolic blood pressure 100 mmHg give 120 / 100 = 1.20, group III (moderate shock).
The normal range is 0.5 to 0.7 (Middleton 2019).
Shock groups in trauma
| Shock index | Group | Hospital mortality | 10 or more blood units before ICU |
|---|---|---|---|
| below 0.6 | I, no shock | 10.9% | not reported |
| 0.6 to below 1.0 | II, mild shock | 9.7% | not reported |
| 1.0 to below 1.4 | III, moderate shock | 22.9% | 31% |
| 1.4 or higher | IV, severe shock | 39.8% | 57% |
Source: Mutschler and colleagues 2013 (Mutschler 2013). Blood units transfused rose from an average of 1.0 in group I to 21.4 in group IV. The authors suggest the shock index may be used to assess hypovolemic shock when point-of-care testing is not available.
Sepsis and pneumonia
A systematic review found that an elevated shock index at hospital presentation predicts mortality in sepsis with high specificity, and called it a moderately accurate predictor that may help as a rule-in tool for high-risk patients (Middleton 2019).
Related calculators
For sepsis, use the qSOFA score calculator and the SOFA score calculator. For upper GI bleeding, see the Glasgow-Blatchford score calculator and the Rockall score calculator, which both use pulse and systolic blood pressure. Other bedside scores are listed under For healthcare professionals.
Sources
- Mutschler M, Nienaber U, Münzberg M, et al. The Shock Index revisited - a fast guide to transfusion requirement? A retrospective analysis on 21,853 patients derived from the TraumaRegister DGU. Crit Care. 2013;17(4):R172. doi:10.1186/cc12851. PMID 23938104. Open access (CC BY 2.0). Shock index definition, four shock groups, mortality and transfusion by group. pmc.ncbi.nlm.nih.gov/articles/PMC4057268/
- Middleton DJ, Smith TO, Bedford R, Neilly M, Myint PK. Shock index predicts outcome in patients with suspected sepsis or community-acquired pneumonia: a systematic review. J Clin Med. 2019;8(8):1144. doi:10.3390/jcm8081144. PMID 31370356. Open access (CC BY 4.0). Normal range 0.5 to 0.7; shock index and mortality in sepsis and pneumonia. pmc.ncbi.nlm.nih.gov/articles/PMC6723191/
Written and maintained by the uncovermyrisk.com editorial team. We do not have a medical reviewer; every claim links to its primary source above. Last reviewed: 2026-11-01. Spotted an error? See About.