About the SOFA Score Calculator
The Sequential (originally Sepsis-related) Organ Failure Assessment (SOFA) score was published by Vincent and colleagues for the European Society of Intensive Care Medicine in 1996. It grades six organ systems from 0 (normal) to 4 (most abnormal): respiration (PaO₂/FiO₂ ratio), coagulation (platelets), liver (bilirubin), cardiovascular (blood pressure and vasopressor support), central nervous system (Glasgow Coma Scale) and renal (creatinine or urine output). The total ranges from 0 to 24.
It is used in intensive care to describe and track organ dysfunction over time, and since the 2016 Sepsis-3 definitions it is the basis of the sepsis definition itself: an acute increase of 2 or more points due to infection, which is associated with an in-hospital mortality greater than 10%. This calculator takes the worst values from the last 24 hours, scores each system and shows which organs contribute most.
SOFA was designed for adult ICU patients. Use the worst value of each variable in the 24-hour period; if a patient has no known pre-existing organ dysfunction, the baseline score is assumed to be zero. Bilirubin and creatinine can be entered in mg/dL or µmol/L.
With the default inputs, the sofa score is 6 / 24. Change any value above to recalculate instantly.
How to use the sofa score calculator
- 1Use the worst value of each variable over the last 24 hours.
- 2Enter PaO₂, FiO₂ and whether the patient is on respiratory support.
- 3Choose mg/dL or µmol/L, then enter platelets, bilirubin and creatinine.
- 4Select the cardiovascular level from MAP and vasopressor use, and enter the GCS.
- 5Add daily urine output if known, then read the total and per-organ scores.
Formula and method
Respiration: PaO₂/FiO₂ ≥ 400 = 0, < 400 = 1, < 300 = 2, < 200 with respiratory support = 3, < 100 with support = 4. Coagulation (platelets ×10³/µL): ≥ 150 = 0, < 150 = 1, < 100 = 2, < 50 = 3, < 20 = 4. Liver (bilirubin mg/dL): < 1.2 = 0, 1.2–1.9 = 1, 2.0–5.9 = 2, 6.0–11.9 = 3, ≥ 12 = 4. CNS (GCS): 15 = 0, 13–14 = 1, 10–12 = 2, 6–9 = 3, < 6 = 4.
Cardiovascular: MAP ≥ 70 = 0, MAP < 70 = 1, dopamine < 5 or dobutamine at any dose = 2, dopamine 5.1–15 or epinephrine/norepinephrine ≤ 0.1 = 3, dopamine > 15 or epinephrine/norepinephrine > 0.1 = 4 (µg/kg/min for ≥ 1 h). Renal (creatinine mg/dL): < 1.2 = 0, 1.2–1.9 = 1, 2.0–3.4 = 2, 3.5–4.9 or urine < 500 mL/day = 3, ≥ 5.0 or urine < 200 mL/day = 4. In µmol/L the table’s own bands are used: bilirubin < 20, 20–32, 33–101, 102–204, > 204; creatinine < 110, 110–170, 171–299, 300–440, > 440.
- PaO₂/FiO₂
- Arterial oxygen tension divided by inspired oxygen fraction
- MAP
- Mean arterial pressure, mmHg
- GCS
- Glasgow Coma Scale (3–15)
Worked examples
Ventilated patient with early multi-organ dysfunction
PaO₂ 90 on 40% oxygen gives a P/F ratio of 225 (2 points). Platelets 140 (1), bilirubin 1.0 (0), MAP < 70 (1), GCS 14 (1) and creatinine 1.4 (1) add up to 6.
Septic shock on norepinephrine
P/F 70 ÷ 0.6 = 117 on the ventilator (3), platelets 45 (3), bilirubin 2.5 (2), norepinephrine > 0.1 (4), GCS 9 (3) and urine 350 mL/day (3, higher than the creatinine score of 2) total 18.
SI units, not ventilated
P/F 186 would score 3 but is capped at 2 without respiratory support. Bilirubin 40 µmol/L falls in the 33–101 band (2) and creatinine 180 µmol/L in the 171–299 band (2); platelets 210, MAP ≥ 70 and GCS 15 score 0, for a total of 6.
Frequently asked questions
What is a normal SOFA score?+
A healthy person with no organ dysfunction scores 0. Unless a patient has known pre-existing organ dysfunction, their baseline SOFA is assumed to be 0 when judging an acute change.
How is SOFA used to define sepsis?+
Sepsis-3 (2016) defines sepsis as life-threatening organ dysfunction caused by infection, operationalised as an acute increase in total SOFA score of 2 points or more, which carries an in-hospital mortality greater than 10%.
What SOFA score is associated with high mortality?+
Mortality rises with the score and with a rising trend. In Ferreira et al. (JAMA 2001, 352 ICU patients in Belgium), initial or highest scores above 11 corresponded to mortality above 80%, and an increase in SOFA during the first 48 hours predicted mortality of at least 50% regardless of the starting score. Local outcomes vary.
What is the difference between SOFA and qSOFA?+
SOFA needs blood tests and a blood gas and scores six organs from 0 to 24; it is used mainly in ICU. qSOFA is a three-item bedside screen (respiratory rate, mentation, systolic BP) for patients outside ICU.
Which values should I use if they change during the day?+
Use the worst value of each variable recorded in the 24-hour period, and repeat the score daily to track whether organ dysfunction is improving or worsening.
For healthcare professionals and education only. This calculator implements a published formula or score but is not a diagnosis and does not replace clinical judgment. Verify inputs and results against the original source before using them in patient care.
Sources
- Vincent JL et al. The SOFA (Sepsis-related Organ Failure Assessment) score to describe organ dysfunction/failure. Intensive Care Med 1996
- Singer M et al. Sepsis-3 definitions (Table 1: SOFA score). JAMA 2016
- Ferreira FL et al. Serial evaluation of the SOFA score to predict outcome in critically ill patients. JAMA 2001