CURB-65 Score Calculator
The CURB-65 score helps assess the severity of community-acquired pneumonia and informs decisions about admission to hospital. It gives one point each for confusion, raised blood urea, a high respiratory rate, low blood pressure, and age 65 or older. This tool totals the points; the management decision belongs to a clinician who weighs the score against the whole clinical picture.
CURB-65 points
C: new confusion = 1
U: urea over 7 mmol/L (BUN over 19 mg/dL) = 1
R: respiratory rate 30 or more per minute = 1
B: systolic blood pressure under 90 mmHg or diastolic 60 mmHg or under = 1
65: age 65 years or older = 1
Score = sum (range 0 to 5)
Each of the five criteria contributes one point if present. The total ranges from 0 to 5. Higher scores are associated with higher mortality and generally support more intensive care settings.
Worked example
An 80-year-old with new confusion, urea 9 mmol/L, respiratory rate 24, and systolic blood pressure 110 scores: confusion (+1) + urea (+1) + age 65 or older (+1) = 3. Scores of 0 to 1 often suggest possible outpatient care, 2 a short stay or supervised care, and 3 or more hospital admission, all as clinical decisions.
Frequently asked questions
What do CURB-65 scores suggest?
Broadly, a score of 0 to 1 indicates low severity often manageable at home, 2 indicates intermediate severity, and 3 to 5 indicates high severity often warranting hospital and possibly intensive care assessment. The thresholds guide, but do not replace, clinical judgement.
What urea threshold is used?
The original score uses a blood urea above 7 mmol/L, which corresponds to blood urea nitrogen (BUN) above about 19 to 20 mg/dL. Select yes if the patient's value exceeds the threshold in whichever unit your lab uses.
Is there a version without urea?
Yes, CRB-65 omits the urea criterion for settings without immediate blood tests and scores 0 to 4. This calculator implements the full CURB-65 with all five criteria.
Is this a management protocol?
No. It computes the severity score. Admission, antibiotics, and level of care are clinical decisions made by a qualified clinician using the full assessment.
Sources
- U.S. National Library of Medicine, StatPearls: CURB-65 / Pneumonia Severity.
- U.S. Centers for Disease Control and Prevention: Pneumonia.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. Educational tool, not medical advice. See our methodology.