APACHE II Score Calculator
APACHE II is a widely used intensive care severity-of-disease classification. It adds an Acute Physiology Score, computed from the worst values of 12 physiologic variables in the first 24 hours, to points for age and chronic health, giving a total from 0 to 71. Higher totals reflect more severe illness and higher group-level predicted mortality. This calculator applies the published point bands to each variable you enter and sums age and chronic health points. Enter the worst value of each variable. This is an educational tool, not a prediction for any individual or a substitute for clinical judgment.
APACHE II scoring
Total = Acute Physiology Score + Age points + Chronic health points
APS = sum of points for 12 physiologic variables (each 0 to 4)
GCS points = 15 - Glasgow Coma Scale
Creatinine points doubled in acute renal failure
Each physiologic variable is mapped to 0 to 4 points by published bands for high and low values. The Glasgow Coma Scale contributes 15 minus its value. Age and chronic health points are added to the physiology total.
APACHE II context
- Range is 0 to 71; higher scores indicate greater severity.
- Uses the worst values from the first 24 hours in intensive care.
- Age points: under 45 = 0, then 2, 3, 5 and 6 for older bands.
- Chronic health adds 2 (elective post-op) or 5 (emergency or nonoperative).
- Designed for groups, not individual prognosis.
APACHE II: frequently asked questions
What is the APACHE II score?
APACHE II (Acute Physiology and Chronic Health Evaluation II) is an intensive care severity-of-disease score. It sums an Acute Physiology Score from 12 measurements, age points and chronic health points, giving a total from 0 to 71. Higher scores indicate greater severity and higher predicted mortality.
What makes up the total?
Total equals the Acute Physiology Score (temperature, mean arterial pressure, heart rate, respiratory rate, oxygenation, arterial pH, sodium, potassium, creatinine, hematocrit, white cell count and Glasgow Coma Scale) plus age points (0 to 6) plus chronic health points (0, 2 or 5).
How are age points assigned?
Under 45 scores 0, 45 to 54 scores 2, 55 to 64 scores 3, 65 to 74 scores 5, and 75 or older scores 6 points.
What are chronic health points?
Patients with severe organ insufficiency or immunocompromise score 5 points if admitted after emergency surgery or for a non-surgical reason, and 2 points if admitted after elective surgery. Otherwise the chronic health points are 0.
Is APACHE II a diagnosis?
No. It is a severity and prognostic score used in intensive care for groups of patients. This calculator is educational and does not predict an individual outcome or replace clinical judgment.
Official sources
- National Library of Medicine (NCBI): APACHE II scoring system literature.
- Centers for Disease Control and Prevention: Critical care and sepsis information.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.