Calculate the qSOFA score (0 to 3) from respiratory rate, mental status and systolic blood pressure to flag sepsis risk in adults with suspected infection.
qSOFA Score Formula
The qSOFA score is the sum of three bedside criteria. Each criterion is worth 1 point when it is present and 0 when it is not, so the total runs from 0 to 3.
qSOFA = C1 + C2 + C3
- qSOFA = total score, from 0 to 3.
- C1 = 1 if mental status is altered (Glasgow Coma Scale below 15), else 0.
- C2 = 1 if respiratory rate is 22 breaths per minute or higher, else 0.
- C3 = 1 if systolic blood pressure is 100 mmHg or lower, else 0.
The calculator adds the three criteria to reach the total. In direct-criteria mode you select Present or Absent for each criterion. In measured-vitals mode you enter the Glasgow Coma Scale score, the respiratory rate, and the systolic blood pressure, and the tool decides each criterion for you and shows which points it counted. A total of 2 or more is a positive qSOFA and marks a higher risk of in-hospital death.
qSOFA Scoring and How It Compares to SIRS and SOFA
The first table summarizes the qSOFA threshold and clinical follow-up; it does not assign an individual mortality probability. The second table sets qSOFA next to the two other tools you will see used around sepsis, so you can tell what each one is for.
| Score | Risk group | Suggested next step |
|---|---|---|
| 0 | Below threshold; sepsis not excluded | Clinical assessment; do not delay care if sepsis is suspected |
| 1 | Below threshold; sepsis not excluded | Keep monitoring; reassess if the patient changes |
| 2 | At least two criteria met | Assess for organ dysfunction, raise monitoring, consider a SOFA score |
| 3 | At least two criteria met | Urgent assessment for organ dysfunction and sepsis |
The next table is the part most single-tool calculators leave out. qSOFA, SIRS, and SOFA are often mentioned together, but they measure different things and are scored differently.
| Tool | Criteria it uses | Range | Positive | Needs labs |
|---|---|---|---|---|
| qSOFA | Altered mentation, respiratory rate 22 or higher, systolic BP 100 or lower | 0 to 3 | 2 or more | No |
| SIRS | Temperature, heart rate above 90, respiratory rate above 20, white cell count | 0 to 4 | 2 or more | Yes (white cell count) |
| SOFA | Six organ systems: lungs, clotting, liver, circulation, brain, kidneys | 0 to 24 | Rise of 2 or more | Yes |
qSOFA is fast because it needs no labs, but it is less sensitive than SIRS, so it can miss early cases. Under the Sepsis-3 definitions, sepsis itself is suspected infection plus an acute rise of 2 or more points in the full SOFA score. That is why a positive qSOFA points you toward a fuller SOFA assessment rather than a diagnosis on its own.
qSOFA Example Problems
Example 1. A patient with suspected pneumonia is confused, so the Glasgow Coma Scale is 13 and mental status counts (C1 = 1). Respiratory rate is 26 breaths per minute, which is 22 or higher (C2 = 1). Systolic blood pressure is 92 mmHg, which is 100 or lower (C3 = 1). The total is 1 + 1 + 1 = 3, a positive qSOFA meeting the two-criterion threshold, so this patient needs prompt assessment for organ dysfunction.
Example 2. A patient with a suspected urinary infection is fully alert, so the Glasgow Coma Scale is 15 and mental status does not count (C1 = 0). Respiratory rate is 24 breaths per minute, which counts (C2 = 1). Systolic blood pressure is 124 mmHg, above 100, so it does not count (C3 = 0). The total is 0 + 1 + 0 = 1, below the qSOFA threshold; this does not establish low clinical risk. One criterion alone does not cross the threshold, but a single fast respiratory rate is still worth watching.
qSOFA Score FAQ
What is a positive qSOFA score?
A total of 2 or 3 is a positive qSOFA. In adults with suspected infection it flags greater risk of poor outcomes at the population level; it does not estimate a particular patient’s chance of death. A positive score is a prompt to look harder for organ dysfunction and to monitor more closely. It is not proof of sepsis by itself.
Does qSOFA diagnose sepsis?
No. Under the Sepsis-3 definitions, qSOFA predicts mortality risk; it does not diagnose sepsis. Sepsis is defined as suspected infection plus an acute rise of 2 or more points in the full SOFA score, which needs laboratory values. A positive qSOFA should prompt that fuller assessment rather than trigger antibiotics on its own.
Should you use qSOFA or SIRS?
They answer different questions. The 2026 Surviving Sepsis Campaign recommends NEWS, NEWS2, MEWS or SIRS over qSOFA when selecting a single hospital screening tool. qSOFA alone can miss sepsis and should not delay assessment or treatment. Neither qSOFA nor SIRS replaces clinical judgment.
