SOFA Score Calculator - Sequential Organ Failure Assessment
Free SOFA score calculator for ICU organ dysfunction assessment. 6 organ systems with mortality prediction, Sepsis-3 criteria evaluation, and delta-SOFA guidance.
SOFA Score Assessment
Score each of the 6 organ systems (0–4 points each)
PaO2/FiO2 ratio. Scores 3–4 require mechanical ventilation/CPAP. If no ABG, estimate from SpO2/FiO2.
Platelet count in thousands per microliter.
Total bilirubin. Most frequently missing SOFA component in practice.
MAP and vasopressor support. All vasopressor doses in mcg/kg/min, administered ≥1 hour.
Use assumed GCS without sedation for sedated patients. Pre-sedation GCS can be carried forward.
Creatinine or urine output (whichever gives higher score). UOP criteria only for scores 3–4.
Sepsis-3 Criteria
FiO2 Estimation Guide
SOFA Score
Enter values to calculate
About This Calculator
What is the SOFA Score?
The SOFA (Sequential Organ Failure Assessment) score is a 6-organ-system ICU scoring tool developed by Jean-Louis Vincent and the European Society of Intensive Care Medicine in 1996. It evaluates respiratory (PaO2/FiO2), coagulation (platelets), liver (bilirubin), cardiovascular (MAP/vasopressors), CNS (GCS), and renal (creatinine/urine output) systems, scoring each 0–4 for a total of 0–24.
Sepsis-3 Definition
SOFA became the cornerstone of the Sepsis-3 definition in 2016. Sepsis is now operationalized as suspected infection plus an acute SOFA increase of ≥2 points from baseline. Baseline SOFA is assumed to be zero in patients without known pre-existing organ dysfunction.
Serial Measurement
Unlike APACHE II or SAPS II (which use first 24h data only), SOFA was explicitly designed for serial daily measurement to track organ dysfunction trajectories. An increasing SOFA over 48 hours predicts ≥50% mortality, while a decreasing SOFA predicts <27% mortality. Maximum SOFA during ICU stay is the strongest single mortality predictor (AUROC 0.90).
Clinical Applications
- Defines sepsis per Sepsis-3 criteria (SOFA increase ≥2 + suspected infection)
- Tracks organ dysfunction trajectory in ICU patients
- Predicts ICU mortality based on initial, maximum, and delta-SOFA scores
- Used for resource allocation and clinical trial endpoints
- Quality metrics and SEP-1 compliance documentation
Formula
SOFA = Respiratory + Coagulation + Liver + Cardiovascular + CNS + Renal (each 0–4, total 0–24)Sum of 6 organ system scores. Each system is scored 0 (normal) to 4 (most dysfunctional). An acute increase of ≥2 points from baseline in a patient with suspected infection defines sepsis per Sepsis-3.
Clinical Considerations
- •SOFA was designed for serial daily measurement — a single score is less informative than a trend.
- •Baseline SOFA is assumed zero unless known pre-existing organ dysfunction. Adjust for chronic conditions.
- •An acute SOFA increase ≥2 + suspected infection = sepsis (Sepsis-3). This is a definition, not a screening tool.
- •Cardiovascular scoring uses vasopressor doses for ≥1 hour. Brief boluses do not count.
- •For sedated patients, use assumed GCS without sedation. Document data source.
Limitations
- •Outdated cardiovascular component — dopamine was first-line in 1996; does not include vasopressin, phenylephrine, or angiotensin II.
- •CNS scoring in sedated patients is subjective — "assumed GCS" has ~70% inter-rater accuracy.
- •No acute vs chronic distinction — CKD patient with baseline creatinine 4.0 scores same as AKI patient.
- •Only 48% of manual SOFA scores fully agree with gold standard; bilirubin most often missing.
- •Not designed for individual patient prediction — population-level estimates with wide confidence intervals.
- •No age component — unlike APACHE II and SAPS II.
- •Racial disparities — creatinine-based renal scoring may disadvantage Black patients.
- •Variable performance — AUROC ranges 0.64–0.90 depending on population and metric used.
Interpretation Guide
| Range | Classification | Recommendation |
|---|---|---|
| <-1 | Minimal Dysfunction | Minimal organ dysfunction. Monitor and re-assess. Likely ward-appropriate if clinically stable. Does not meet Sepsis-3 threshold (requires SOFA increase ≥2). |
| 2-5 | Mild Dysfunction | Mild dysfunction. If SOFA increased ≥2 from baseline with suspected infection, meets Sepsis-3 criteria for sepsis. ICU monitoring recommended. Initiate Hour-1 Sepsis Bundle if sepsis suspected. |
| 6-9 | Moderate Dysfunction | Significant organ failure. Aggressive management warranted. Serial SOFA trending recommended — increasing SOFA over 48h predicts ≥50% mortality. |
| 10-14 | Severe Dysfunction | Severe multi-organ failure with high mortality risk. Consider goals-of-care discussion. Serial SOFA trending critical for trajectory assessment. |
| 15-24 | Extreme Dysfunction | Extreme multi-organ failure with very high mortality. Goals-of-care discussion strongly warranted. Maximum SOFA ≥15 during ICU stay approaches 90% mortality. |
Frequently Asked Questions
What is the SOFA score?
The SOFA (Sequential Organ Failure Assessment) score evaluates 6 organ systems — respiratory (PaO2/FiO2), coagulation (platelets), liver (bilirubin), cardiovascular (MAP/vasopressors), CNS (GCS), and renal (creatinine/urine output). Each is scored 0–4, totaling 0–24. It was developed in 1996 for serial daily measurement of organ dysfunction in ICU patients.
How does SOFA relate to the Sepsis-3 definition?
Sepsis-3 (2016) defines sepsis as suspected infection plus an acute SOFA score increase of ≥2 points from baseline. Baseline SOFA is assumed to be zero in patients without known pre-existing organ dysfunction. Septic shock is further defined as sepsis plus vasopressors to maintain MAP ≥65 mmHg AND lactate >2 mmol/L despite adequate fluid resuscitation.
What is the difference between SOFA and qSOFA?
SOFA is a 6-organ-system tool requiring laboratory values, used to define and diagnose sepsis in the ICU (AUROC 0.74). qSOFA is a 3-item bedside screening tool (RR, SBP, GCS) requiring no labs, designed for non-ICU settings. qSOFA prompts further SOFA evaluation when positive (≥2). Note: SSC 2021 recommends against qSOFA as a sole screening tool.
What is delta-SOFA?
Delta-SOFA is the change in SOFA score over time, typically comparing current to baseline or admission SOFA. An acute increase of ≥2 points defines sepsis (Sepsis-3). Increasing SOFA over the first 48 hours predicts ≥50% mortality, while decreasing SOFA predicts <27% mortality. Delta-SOFA is accepted by the EMA as a surrogate efficacy marker in sepsis trials.
What is maximum SOFA?
Maximum SOFA is the highest SOFA score recorded during an ICU stay. It is the single strongest mortality predictor (AUROC 0.90), outperforming initial SOFA (0.79), mean SOFA (0.88), and delta-SOFA (0.84). Mortality ranges from 3.2% with no organ failure to 91.3% when all 6 organs are failing.
How does SOFA compare to APACHE II?
SOFA and APACHE II answer different clinical questions. SOFA (6 systems, 0–24) tracks organ dysfunction serially and defines sepsis. APACHE II (12 physiology variables + age + chronic health, 0–71) provides a one-time admission severity estimate. SOFA is measured daily; APACHE II uses only first-24-hour data. Neither replaces the other.
How is the cardiovascular SOFA component scored?
Cardiovascular SOFA: 0 = MAP ≥70 without vasopressors; 1 = MAP <70; 2 = dopamine ≤5 or dobutamine (any dose); 3 = dopamine >5 or epinephrine/norepinephrine ≤0.1 mcg/kg/min; 4 = dopamine >15 or epinephrine/norepinephrine >0.1 mcg/kg/min. All vasopressor doses in mcg/kg/min, administered for ≥1 hour.
What if PaO2 is not available for respiratory SOFA?
When ABG is unavailable, SpO2/FiO2 ratio can estimate PaO2/FiO2 (Rice et al. 2007: SpO2/FiO2 of 235 ≈ PaO2/FiO2 of 200). SOFA-2 (2025) formally adds SpO2/FiO2 as an alternative respiratory measure.
How should sedated patients be scored for CNS?
For sedated patients, use the "assumed GCS" — the score without sedation. Pre-sedation GCS can be carried forward. This is the least accurately measured SOFA component (~70% inter-rater accuracy). Document whether GCS was directly assessed or carried forward.
What is the SOFA-2 update?
SOFA-2 was published in October 2025 (JAMA) based on 3.34 million patients across 1,300+ ICUs in 9 countries. Key changes: added SpO2/FiO2 for respiratory scoring, simplified cardiovascular to norepinephrine/epinephrine equivalents, updated all thresholds, and renamed organ systems. SOFA-2 AUROC improved to 0.79 vs 0.77 for SOFA-1. Original SOFA remains the standard in Sepsis-3 definitions as of early 2026.
What SOFA score indicates high mortality?
Initial SOFA 10–11 is associated with ~50% ICU mortality, and scores ≥12 approach 95% mortality (Ferreira et al. 2001). Maximum SOFA ≥15 during ICU stay has >80% mortality approaching 90%. Mortality with all 6 organs failing is 91.3% (Moreno et al. 1999).
What are the limitations of the SOFA score?
Key limitations: (1) Outdated cardiovascular component — does not include vasopressin or angiotensin II. (2) GCS in sedated patients is subjective (70% accuracy). (3) No distinction between acute and chronic organ dysfunction. (4) Bilirubin frequently missing in practice. (5) Racial disparities — creatinine-based renal scoring may disadvantage Black patients. (6) Only 48% of manual calculations fully agree with gold standard.
References
1. Vincent JL, Moreno R, Takala J, et al.. The SOFA (Sepsis-related Organ Failure Assessment) score to describe organ dysfunction/failure. Intensive Care Medicine. 1996
View Source →2. Moreno R, Vincent JL, Matos R, et al.. The use of maximum SOFA score to quantify organ dysfunction/failure in intensive care. Intensive Care Medicine. 1999
3. Ferreira FL, Bota DP, Bross A, et al.. Serial evaluation of the SOFA score to predict outcome in critically ill patients. JAMA. 2001. doi: 10.1001/jama.286.14.1754
4. Singer M, Deutschman CS, Seymour CW, et al.. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016. doi: 10.1001/jama.2016.0287
View Source →5. Seymour CW, Liu VX, Iwashyna TJ, et al.. Assessment of Clinical Criteria for Sepsis. JAMA. 2016. doi: 10.1001/jama.2016.0288
6. Ranzani OT, Vincent JL, et al.. SOFA-2 Score — Updated Sequential Organ Failure Assessment. JAMA. 2025
Last updated: 2026-02-25
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