SOFA Score Calculator (Sequential Organ Failure Assessment)

The Sequential Organ Failure Assessment (SOFA) score, first defined by Vincent and colleagues in 1996, grades the function of six organ systems on a 0–4 scale — 0 for normal, 4 for the most severe dysfunction — and adds them for a total from 0 to 24. There is no arithmetic beyond unit conversion and summation; each system is a threshold lookup taken directly from the original definition.

The six systems and their cut-offs:

• Respiration— PaO₂/FiO₂ (mmHg): <400 → 1, <300 → 2, <200 with respiratory support → 3, <100 with support → 4. Below 200 without support caps at 2.
• Coagulation— platelets (×10³/µL): <150 → 1, <100 → 2, <50 → 3, <20 → 4.
• Liver — bilirubin: ≥1.2 → 1, ≥2.0 → 2, ≥6.0 → 3, ≥12.0 mg/dL → 4.
• Cardiovascular— takes the higher of low MAP (<70 → 1) and vasopressor dose (dopamine ≤5 or any dobutamine → 2; dopamine >5 or epinephrine/norepinephrine ≤0.1 → 3; dopamine >15 or epinephrine/norepinephrine >0.1 µg/kg/min → 4).
• CNS — Glasgow Coma Scale: 13–14 → 1, 10–12 → 2, 6–9 → 3, 3–5 → 4.
• Renal— takes the higher of creatinine (≥1.2 → 1, ≥2.0 → 2, ≥3.5 → 3, ≥5.0 mg/dL → 4) and urine output (<500 → 3, <200 mL/day → 4).

Conventional and SI units are interchangeable: the tool converts with bilirubin(mg/dL) = µmol/L ÷ 17.1 and creatinine(mg/dL) = µmol/L ÷ 88.4, then compares in mg/dL against the original cut-offs. A missing value scores 0, the standard convention that an unmeasured organ is assumed normal.

The total maps to a published ICU-mortality band from the serial-evaluation cohorts (Ferreira 2001 (JAMA) / Vincent 1998 (Crit Care Med)): under about 10% at 0–6, rising through 15–20% (7–9), 40–50% (10–12) and 50–60% (13–14) to over about 80% at 15 or more. Those figures describe populations, not an individual prediction.

Finally, the calculator applies the Sepsis-3 rule (Singer 2016): in a patient with suspected or confirmed infection, an acute rise in total SOFA of 2points or more from baseline meets the criterion for sepsis. Baseline is assumed 0 in patients without known pre-existing organ dysfunction, so the delta — not the absolute total — is what the tool tests. Every subscore is also re-derived through a second, independent code path and the two totals are compared, which is what the “cross-checked” badge confirms.

Unit-conversion check: bilirubin 205 µmol/L ÷ 17.1 = 11.99 mg/dL, which is still below 12.0, so the liver subscore is 3 (not 4); creatinine 442 µmol/L ÷ 88.4 = 5.0 mg/dL reaches the top renal band at 4. Enter either unit and the subscore is identical.

• Vincent JL, Moreno R, Takala J, et al. The SOFA (Sepsis-related Organ Failure Assessment) score to describe organ dysfunction/failure. Intensive Care Med. 1996;22(7):707–710 (original six-system definition and 0–4 cut-offs)
• Ferreira FL, Bones Peres D, Bross A, Mélot C, Vincent JL. Serial evaluation of the SOFA score to predict outcome in critically ill patients. JAMA. 2001;286(14):1754–1758 (per-total mortality bands)
• Singer M, Deutschman CS, Seymour CW, et al. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016;315(8):801–810 (acute change in total SOFA ≥ 2 criterion)

The cut-offs (Vincent 1996 (Intensive Care Med — original SOFA definition)), mortality bands (Ferreira 2001 (JAMA) / Vincent 1998 (Crit Care Med)) and the Sepsis-3 criterion on this page were last cross-checked against these sources on 2026-07-17. This tool is for education and reference only; it aids, but does not replace, assessment by a qualified clinician, and it computes the adult SOFA score, not pediatric SOFA (pSOFA).