Free SOFA Score Calculator

Understanding the Sequential Organ Failure Assessment (SOFA) Score

The Sequential Organ Failure Assessment (SOFA) score is a standardized tool used in intensive care units to evaluate the degree of organ dysfunction in critically ill patients. Originally developed in 1994 by a consensus of critical care physicians, the system was first named “Sepsis-Related Organ Failure Assessment.” Its name was later changed to reflect its broader applicability beyond sepsis. By examining six separate organ systems, the SOFA calculator assigns a score from 0 (normal function) to 4 (severe failure) for each system, producing a total that reflects the overall organ failure burden. This online SOFA score calculator provides quick, consistent calculations for both clinical tracking and research purposes.

Key Variables and Scoring Criteria

The six organ systems assessed by SOFA are respiratory, coagulation, liver, cardiovascular, central nervous system, and renal. Each is graded independently according to the following criteria.

Respiratory, Coagulation, and Liver

Score	Respiration (PaO₂/FiO₂, mmHg)	Coagulation (Platelets ×10³/μL)	Liver (Bilirubin, mg/dL)
0	>400	>150	<1.2
1	≤400	≤150	1.2–1.9
2	≤300	≤100	2.0–5.9
3	≤200*	≤50	6.0–11.9
4	≤100*	≤20	≥12.0

Cardiovascular, Central Nervous System, and Renal

Score	Cardiovascular (Hypotension)	CNS (Glasgow Coma Scale)	Renal (Creatinine mg/dL or urine output)
0	No hypotension	>15	<1.2
1	MAP < 70 mmHg	13–14	1.2–1.9
2	Dopamine ≤ 5** or dobutamine (any)	10–12	2.0–3.4
3	Dopamine > 5** or epinephrine ≤ 0.1** or norepinephrine ≤ 0.1**	6–9	3.5–4.9 or UO < 500 mL/day
4	Dopamine > 15** or epinephrine > 0.1** or norepinephrine > 0.1**	<6	≥5.0 or UO < 200 mL/day

*Values obtained while the patient is on respiratory support.
**Adrenergic agents administered for at least one hour; doses given in μg/kg/min.

For the central nervous system assessment, the Glasgow Coma Scale (GCS) is used. The overall SOFA score is the sum of all six component scores, ranging from 0 (no dysfunction) to 24 (maximum failure).

Prognostic Value and Mortality Risk

The SOFA score is a strong predictor of outcome in ICU patients. An increase of even a few points during the first 48 hours of admission is clinically significant, correlating with a mortality rate of at least 50 %, regardless of the starting value.

Data from a landmark study by Ferreira et al. illustrate the relationship between SOFA scores and hospital mortality:

Initial vs. Highest SOFA Score and Associated Mortality

SOFA Score Range	Mortality – Initial Score (%)	Mortality – Highest Score (%)
0–1	0	–
2–3	4.4	4.5
4–5	20.2	46.1
6–7	21.5	18.2
8–9	33.3	26.3
10–11	50.0	45.8
12–14	95.2	80.0
>14	95.2	89.7

Mean SOFA Score and Mortality

Mean SOFA Score Range	Mortality (%)
0–1	0
1.1–2	4.4
2.1–3	20.0
3.1–4	36.1
4.1–5	73.1
>5.1	84.4

These figures demonstrate that both the initial score and the trend over time carry prognostic weight. The highest score reached during the ICU stay often yields the strongest mortality association.

Using the SOFA Calculator in Practice

This online SOFA calculator is designed for easy, reproducible scoring, making it useful for bedside tracking and research. However, it must be emphasized that the tool is an aid and cannot replace the comprehensive assessment of a qualified healthcare professional. Clinical decisions should always be made in the context of the full patient picture.

For clinicians interested in related scores, the simplified qSOFA (quick SOFA) version is available for rapid sepsis screening, and the SAPS II (Simplified Acute Physiology Score II) provides another method for ICU mortality risk evaluation.