ISS Calculator — Injury Severity Score
The Injury Severity Score (ISS) is the standard anatomical trauma scoring system used worldwide in emergency medicine and trauma surgery. Select the highest AIS severity for each of the six body regions to get the ISS and its classification.
Head & Neck (AIS)
Face (AIS)
Chest (AIS)
Abdomen / Pelvis (AIS)
Extremities (AIS)
External / Skin (AIS)
Serious injury — major trauma threshold
- 1
Top 3 AIS region scores
A = 3, B = 2, C = 2Only the three highest-scoring body regions contribute to ISS. - 2
Square each score
3² + 2² + 2² = 9 + 4 + 4 - 3
Injury Severity Score
9 + 4 + 4 = 17
Jak tato kalkulačka funguje?
ISS = (top AIS score)² + (2nd highest AIS)² + (3rd highest AIS)², with AIS scored 0–6 per body region. Score ≥ 16 = major trauma; ≥ 25 = critical. If any region is AIS 6, ISS = 75 automatically. Select each region's AIS severity to compute the score instantly.
Vzorec
How this is calculated
The ISS was developed by Baker et al. (1974) and uses the Abbreviated Injury Scale (AIS) as its building block. The body is divided into six regions: Head & Neck, Face, Chest, Abdomen/Pelvis, Extremities, and External/Skin. A trained clinician assigns each injured region an AIS severity score from 0 (none) to 6 (maximum, unsurvivable). The calculator then picks the three highest-scoring regions, squares each score, and sums the squares to produce the ISS (range 0–75).
An ISS of 16 or above is the conventional definition of major trauma, which typically triggers activation of a trauma team in hospital protocols. An AIS of 6 in any single region is defined as an unsurvivable injury and automatically maps to the maximum ISS of 75, regardless of other regions.
Limitations: ISS counts only the worst injury per region, so patients with multiple severe injuries in the same body area are underscored. The New Injury Severity Score (NISS) corrects this by taking the three highest AIS scores from any region, not one per region. ISS also does not incorporate physiological parameters (e.g., blood pressure, GCS); combined scores like TRISS or APACHE add those dimensions for mortality prediction.
Často kladené otázky
An ISS of 16 or above is the internationally accepted threshold for major trauma. Patients scoring 16+ are generally managed by a full trauma team. An ISS of 25 or higher is often used to define critical trauma in research and audit settings.
The AIS is scored by a clinician or trauma coder based on the specific injury description — typically from imaging reports, operative findings, or autopsy notes. AIS 1 (minor) might be a small laceration; AIS 4 (severe) could be a tension pneumothorax; AIS 5 (critical) might be an open pelvic fracture with haemorrhage. Each region receives only one AIS — the worst injury in that region.
The ISS uses the three highest AIS scores from three different body regions. The New ISS (NISS, Osler 1997) uses the three highest AIS scores from any region, allowing multiple injuries in the same region to count. NISS generally predicts mortality better in patients with multiple severe injuries to the same body area (e.g. multiple chest injuries), while ISS remains the international standard for trauma registry and audit.
Také známé jako
TG we-Calculate Editorial Team. (2026). ISS Calculator — Injury Severity Score [Online calculator]. TG we-Calculate. https://we-calculate.com/cs/calculator/iss-calculator
TG we-Calculate Editorial Team. "ISS Calculator — Injury Severity Score." TG we-Calculate. 2026. https://we-calculate.com/cs/calculator/iss-calculator.
TG we-Calculate Editorial Team, "ISS Calculator — Injury Severity Score," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/cs/calculator/iss-calculator
@misc{wecalculate_iss_calculator, title = {ISS Calculator — Injury Severity Score}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/cs/calculator/iss-calculator}}, year = {2026}, note = {TG we-Calculate} }
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