Classic SOFA-1 Calculator
Calculate the original 1996 Classic SOFA-1 score from the worst eligible values in one defined 24-hour window, with an optional comparable-baseline change.
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About
Classic SOFA-1 is the original 1996 six-organ organ-dysfunction description scale: respiration, coagulation, liver, cardiovascular, central nervous system, and renal. This page uses one explicitly defined adult 24-hour window and the highest applicable Classic SOFA-1 category for each organ; the six worst categories do not need to occur simultaneously. [1, 2, 3]
The form accepts categories already selected from documented measurements or support records, not raw PaO₂, platelets, bilirubin, GCS, creatinine, urine output, or drug doses. It cannot verify those classifications. It returns a complete 0–24 total, the renal scoring basis, and an optional arithmetic delta from a comparable baseline. It does not diagnose sepsis or septic shock, provide an individual mortality probability, or decide antibiotics, cultures, fluids, vasopressors, respiratory support, ICU placement, or limits of life support; it also does not calculate SOFA-2 or qSOFA. [5, 7, 8, 9, 10]
Formula
Interpretation
| Output | Formal range | Meaning | What it does not mean |
|---|---|---|---|
| Submitted Classic SOFA-1 | 0–24 | Six-organ current-window total | Not a sepsis diagnosis |
| Entered baseline | 0–24 or blank | User-submitted comparable score | Not a page-inferred value |
| Delta | −24 to +24 or absent | Arithmetic change | Not infection or causal evidence |
| Renal basis | Creatinine / urine / higher of both | Renal data source | Not a kidney diagnosis |
A higher or rising SOFA has been associated with worse outcomes in groups, but cohorts, timing, data extraction, and support definitions differ. This page provides no fixed mortality rate and no dynamic low/high-risk label. [3, 4]
Classic SOFA-1 organ categories, delta rules, and current version limits
Defined 24-hour assessment contract
Use an adult Classic SOFA-1 window that was defined before selecting categories. “Worst” means the highest applicable SOFA points, not the numerically largest value: platelets and GCS usually score more at lower values, whereas bilirubin, creatinine, and vasoactive dose usually score more at higher categories. The six worst categories need not be simultaneous. Do not mix dates, admissions, windows, or noncomparable extraction rules; this page cannot verify the source record or window. [2, 3, 7]
Complete Classic SOFA-1 table
The visible table is a transcription aid for the original six-organ 0–4 categories; the frozen scorer remains the source of the submitted result. [1, 7]
| Organ | 0 points | 1 point | 2 points | 3 points | 4 points | Key operational limit |
|---|---|---|---|---|---|---|
| Respiration | P/F ≥400 | 300–399 | <300 without qualifying support, or 200–299 with support | 100–199 with qualifying support | <100 with qualifying support | Support must meet the applicable local, research, or audit definition. |
| Coagulation | ≥150 | 100–149 | 50–99 | 20–49 | <20 | Platelet units must follow the adopted table. |
| Liver | <1.2 mg/dL | 1.2–1.9 | 2.0–5.9 | 6.0–11.9 | ≥12.0 | Use a documented category; this page does not convert units. |
| Cardiovascular | MAP ≥70 without classic drug category | MAP <70 without classic drug category | Dopamine ≤5 or dobutamine | Dopamine >5–15 or epinephrine/norepinephrine ≤0.1 | Dopamine >15 or epinephrine/norepinephrine >0.1 | µg/kg/min; continuous ≥1 hour; choose the highest applicable classic category. |
| CNS | GCS 15 | 13–14 | 10–12 | 6–9 | <6 | Use a reliable documented GCS; the page does not perform the examination. |
| Renal | Creatinine <1.2 or urine ≥500 mL/24 h | Creatinine 1.2–1.9 | Creatinine 2.0–3.4 | Creatinine 3.5–4.9 or urine 200–499 | Creatinine ≥5.0 or urine <200 | Use the higher available creatinine/urine category; both unavailable withhold the total. |
Category selection and data transparency
The form receives already classified categories. It does not collect or calculate raw P/F, platelets, bilirubin, GCS, creatinine, urine output, MAP, or vasoactive doses, and it cannot confirm that a chosen category matches the original measurement. When overlapping historical definitions exist, select the highest applicable category under the adopted contract; if no reliable category exists, leave it unavailable rather than guessing. [7]
Respiratory and cardiovascular operational limits
Respiration 3 or 4 requires both the P/F threshold and a qualifying respiratory-support definition. Ordinary low-flow oxygen is not automatically qualifying; HFNC, NIV, invasive ventilation, ECMO, or another modern device must be interpreted under the local, research, or audit definition. Cardiovascular categories use classic dopamine, dobutamine, epinephrine, or norepinephrine in µg/kg/min for continuous administration of at least 1 hour. Multiple classic drugs are not added; choose the highest applicable category. Vasopressin, phenylephrine, milrinone, angiotensin II, and norepinephrine-equivalent conversions are not silently substituted, and the page does not choose treatment. [1, 7]
Renal availability and higher-score rule
Creatinine-only, urine-output-only, and higher-of-both paths are distinct. With both measures available, the higher validated score is used; with one measure unavailable, the other can produce a complete total, but the missing alternative could have produced a higher category. Both unavailable withhold the total. Unavailable does not mean normal, and Classic SOFA-1 does not add dialysis or kidney-replacement-therapy points from SOFA-2. [1, 7, 9, 10]
| Creatinine | Urine output | Result |
|---|---|---|
| Available | Unavailable | Creatinine only |
| Unavailable | Available | Urine output only |
| Available | Available | Higher of both |
| Unavailable | Unavailable | No complete total |
Baseline, delta, and Sepsis-3
Sepsis-3 describes sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection; an acute Classic SOFA-1 increase of at least 2 from baseline is an operational organ-dysfunction criterion in suspected infection. When prior acute or chronic dysfunction is unknown, that framework may assume baseline 0, but this page never fills 0 automatically. Delta can be positive, zero, or negative and cannot by itself establish infection, causality, timing, or sepsis. [3, 5, 6]
Classic SOFA-1, SOFA-2, qSOFA, APACHE II, and SAPS II
These models have different variables, thresholds, time contracts, and purposes. qSOFA is a three-variable prompt; APACHE II and SAPS II are distinct weighted severity/prognostic models; SOFA-2 is a separately developed updated descriptive scale. Scores cannot be added, converted, or substituted. [9, 10, 13]
| Model | Inputs | Time frame | Primary purpose | Why not interchangeable |
|---|---|---|---|---|
| Classic SOFA-1 | Six organ categories | Defined 24-hour window | Describe organ dysfunction | This page’s frozen model |
| SOFA-2 | Updated organ/support standards | Version-specific | Updated descriptive scale | Different thresholds and subcriteria; not an option here |
| qSOFA | Three bedside variables | Prompt, not six-organ window | Separate suspected-infection prompt | Cannot be added to or converted from SOFA |
| APACHE II | Physiology, age, chronic health | First ICU 24 hours | Different severity model | Different variables, weights, and purpose |
| SAPS II | Weighted ICU predictors | Model-specific window | Different severity/prognostic model | Scores are not equivalent |
Worked examples from the frozen implementation
- Zero: six organs score 0, creatinine is category 0, urine output is unavailable, baseline is blank → total 0; renal basis is creatinine only.
- Maximum: six organs score 4, including creatinine 4 and urine output 4 → total 24, without an individual mortality probability or treatment recommendation.
- Mixed 16: respiration 3, coagulation 1, liver 2, cardiovascular 3, CNS 4, creatinine 2 and urine output 3 → renal 3 by higher of both and total 16.
- Renal availability: creatinine 2 plus unavailable urine → 2, creatinine only; unavailable creatinine plus urine 3 → 3, urine only; both available 2 and 3 → 3, higher of both; both unavailable → no total.
- Baseline and delta: current total 16 with baseline 14 → +2; current total 3 with baseline 5 → −2. Both are arithmetic differences, not sepsis diagnoses.
- Respiration: P/F 80 with qualifying support can be category 4, while P/F 80 without qualifying support can be category 2. The page cannot verify either raw P/F or support classification.
These examples are generated from the frozen implementation and describe arithmetic only. [1, 4, 7]
Current 2026 guideline and SOFA-2 context
The 2026 Surviving Sepsis Campaign says that for hospitalized acutely ill adults, NEWS/NEWS2, MEWS, or SIRS are preferred over qSOFA as a single sepsis screening tool; sepsis remains a clinical diagnosis, and no single tool, biomarker, or test can confirm or exclude it alone. This page is not a sepsis screener and provides no antibiotics, cultures, lactate, fluids, vasopressors, or other treatment advice. [8]
SOFA-2’s main study and methods paper were published online October 29, 2025; the main study was corrected January 29, 2026 for minor typographical errors. The methods paper was corrected January 26, 2026 for Tables 3 and 4 and March 4, 2026 for Hallie C. Prescott’s name. SOFA-2 uses the same six-organ framework but updated thresholds, modern support modes, and new subcriteria. It is not an option here: the methods paper states that the sponsoring bodies of the International Sepsis-3 Definitions must decide whether it replaces SOFA-1, and the 2026 reply emphasizes a descriptive organ-dysfunction scale rather than a personal predictive score. [9, 10, 11, 12, 13]
Important limitations
Interpretation can be limited by pediatric age, pregnancy, non-ICU or specialty ICU settings, sedation, paralysis, intubation, missing GCS, HFNC and other support definitions, ECMO, nonclassic vasoactive drugs, dose formulation differences, dialysis or KRT, chronic or acute-on-chronic dysfunction, transient abnormalities, data collected after treatment, mismatched windows, missing laboratory data, bilirubin or platelet measurement variation, unreliable urine collection, baseline noncomparability, SOFA-2 substitution, and chart-abstraction error. A low score does not mean safe; a high score does not automatically mean death or treatment limitation; an unstable patient should not wait for an online calculator. SOFA does not replace continuous clinical assessment. [7, 8, 10]
References
- 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;22:707–710. PMID 8844239. DOI 10.1007/BF01709751.
- Vincent JL, de Mendonça A, Cantraine F, et al. Use of the SOFA score to assess the incidence of organ dysfunction/failure in intensive care units. Crit Care Med. 1998;26(11):1793–1800. PMID 9824069. DOI 10.1097/00003246-199811000-00016.
- Moreno R, Vincent JL, Matos R, et al. The use of maximum SOFA score to quantify organ dysfunction/failure in intensive care. Intensive Care Med. 1999;25(7):686–696. PMID 10470572. DOI 10.1007/s001340050931.
- Ferreira FL, Bota DP, 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. PMID 11594901. DOI 10.1001/jama.286.14.1754.
- 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. PMID 26903338. PMCID PMC4968574. DOI 10.1001/jama.2016.0287.
- Seymour CW, Liu VX, Iwashyna TJ, et al. Assessment of Clinical Criteria for Sepsis. JAMA. 2016;315(8):762–774. PMID 26903335. DOI 10.1001/jama.2016.0288.
- Lambden S, Laterre PF, Levy MM, Francois B. The SOFA score—development, utility and challenges of accurate assessment in clinical trials. Crit Care. 2019;23:374. PMID 31775846. DOI 10.1186/s13054-019-2663-7.
- Prescott HC, Antonelli M, Alhazzani W, et al. Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2026. Crit Care Med. 2026. DOI 10.1097/CCM.0000000000007075.
- Ranzani OT, Singer M, Salluh JIF, et al. Development and Validation of the Sequential Organ Failure Assessment (SOFA)-2 Score. JAMA. Published online October 29, 2025. PMID 41159833. DOI 10.1001/jama.2025.20516. Corrected January 29, 2026 for minor typographical errors.
- Moreno R, Rhodes A, Ranzani O, et al. Rationale and Methodological Approach Underlying the Development of the SOFA-2 Score. JAMA Netw Open. 2025;8(10):e2545040. DOI 10.1001/jamanetworkopen.2025.45040. Corrected January 26, 2026 for Tables 3 and 4 and March 4, 2026 for Hallie C. Prescott's name.
- Error in Tables. JAMA Netw Open. 2026;9(1):e2560466. DOI 10.1001/jamanetworkopen.2025.60466. Correction published January 26, 2026: Table 3 footnote ratio data and Table 4 renal organ-system wording.
- Error in Byline. JAMA Netw Open. 2026;9(3):e264615. DOI 10.1001/jamanetworkopen.2026.4615. Correction published March 4, 2026 for Hallie C. Prescott's name.
- Ranzani OT, Singer M, Moreno RP. Clarifying the SOFA-2 Score—Reply. JAMA. 2026;335(15):1362–1363. DOI 10.1001/jama.2026.0313.
FAQ
The six systems are respiration, coagulation, liver, cardiovascular, central nervous system (GCS), and renal. Each contributes a category from 0 through 4; this page accepts documented categories rather than reconstructing the underlying examination or laboratory result.
Sources: [1]
Classic SOFA workflows use the most abnormal eligible category in a documented assessment window, and serial or maximum scores depend on the chosen window. Define the adult 24-hour period before selecting values; the page cannot verify dates, extraction rules, or whether categories came from comparable records.
Sepsis-3 describes sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection and uses an acute SOFA increase of at least 2 from baseline as an operational organ-dysfunction criterion in suspected infection. The score or delta alone does not establish infection, causality, or sepsis.
The Sepsis-3 framework may assume baseline 0 when prior acute or chronic organ dysfunction is unknown, but this calculator never fills it automatically. Enter 0 explicitly only when that is the documented comparison you intend to use; otherwise leave baseline blank.
Sources: [5]
This page does not make that claim. SOFA-2 and Classic SOFA-1 are not interchangeable, and the methodology paper states that the sponsoring bodies of the International Sepsis-3 Definitions must decide whether a replacement occurs. The 2026 reply describes SOFA-2 as a descriptive organ-dysfunction scale rather than a personal predictive score.
Creatinine and 24-hour urine output are alternative renal criteria. A single reliable measure can produce a renal score; when both are available, this implementation uses the higher validated category. When both are unavailable, it withholds the complete total rather than treating missing data as normal.
Sedation, paralysis, intubation, intoxication, language or hearing barriers, and baseline neurologic impairment can confound a GCS. Use a reliable time-recorded protocol-defined category; this page cannot reconstruct an unconfounded examination or guess an unavailable score.
Sources: [7]
The 3- and 4-point respiratory categories require both the P/F threshold and a qualifying support definition. Ordinary low-flow oxygen is not automatically qualifying; follow the applicable local, research, or audit protocol because this page does not collect or verify the raw measurements or device definition.
A Classic SOFA-1 total describes submitted organ categories. It does not select antibiotics, cultures, lactate testing, fluids, vasopressors, respiratory support, ICU placement, dialysis, referral, or limits of life support; those decisions require clinical assessment and the applicable pathway.
Related Calculators
qSOFA
Calculate the original adult Sepsis-3 qSOFA prognostic prompt from respiratory rate, altered mentation, and systolic blood pressure.
APACHE II
Reproduce the 1985 adult general-ICU APACHE II severity score from worst first-24-hour physiology, age and defined chronic-health points.
GCS
Record the standard adult Glasgow Coma Scale eye, verbal, and motor responses, including documented not-testable components without creating a misleading total.
Disclaimer
Educational and informational reference only. Not intended to replace professional medical advice, diagnosis, treatment, or independent verification.