Calculator
Use this tool for adult community-acquired pneumonia severity support in hospital settings. It is not a substitute for diagnosis, escalation decisions, or emergency assessment.
Formula Used
The CURB-65 total equals the sum of five binary criteria. Each positive criterion adds 1 point. The final score ranges from 0 to 5.
- C = Confusion present → 1 point
- U = Blood urea above 7 mmol/L → 1 point
- R = Respiratory rate at least 30/min → 1 point
- B = Systolic BP below 90 mmHg or diastolic BP 60 mmHg or less → 1 point
- 65 = Age 65 years or older → 1 point
CURB-65 Score = C + U + R + B + Age Criterion
Interpretation Guide
- 0–1 points: Low risk
- 2 points: Intermediate risk
- 3–5 points: High risk
How to Use This Calculator
- Choose whether the patient has new confusion or disorientation.
- Enter blood urea in mmol/L, or BUN in mg/dL and select the correct unit.
- Enter respiratory rate, systolic blood pressure, diastolic blood pressure, and age.
- Press Calculate CURB-65 Score to display the total score above the form.
- Review the risk band, criterion-by-criterion breakdown, and graph. Use the CSV or PDF buttons to export the results.
Example Data Table
| Example | Confusion | Urea / BUN | Respiratory Rate | Blood Pressure | Age | Score | Risk Band |
|---|---|---|---|---|---|---|---|
| Patient A | No | 4.8 mmol/L | 22/min | 118 / 74 mmHg | 44 | 0 | Low |
| Patient B | No | 7.4 mmol/L | 26/min | 132 / 78 mmHg | 66 | 2 | Intermediate |
| Patient C | No | 8.1 mmol/L | 31/min | 98 / 62 mmHg | 70 | 3 | High |
| Patient D | Yes | 6.5 mmol/L | 28/min | 84 / 58 mmHg | 67 | 3 | High |
8 FAQs
1) What does CURB-65 measure?
It estimates severity and mortality risk in adults with community-acquired pneumonia using five simple bedside and lab criteria.
2) When should this score be used?
It is commonly used during hospital assessment of adult community-acquired pneumonia to support risk stratification and place-of-care decisions.
3) Why does this calculator allow BUN and urea units?
Some labs report urea in mmol/L, while others report BUN in mg/dL. This page converts BUN to an approximate urea-equivalent threshold for scoring.
4) Is the score enough to decide admission?
No. Oxygenation, sepsis risk, frailty, pregnancy, dehydration, comorbid illness, imaging, and clinician judgment still matter.
5) What does a score of 0 or 1 suggest?
It suggests lower predicted mortality risk. Stable patients may sometimes be managed outside hospital if other concerns are absent.
6) What does a score of 2 suggest?
It indicates intermediate risk. These patients need closer review, because admission or closely supervised management may be appropriate.
7) What does a score of 3 to 5 suggest?
It indicates high risk and usually supports urgent hospital-based care, with escalation based on the patient’s full clinical status.
8) Can a patient use this tool alone at home?
No. Breathing difficulty, confusion, blue lips, low blood pressure, chest pain, or rapid deterioration need urgent medical attention.