CURB-65 Pneumonia Severity Score Calculator

Enter Calculation

Confusion (new onset / abbreviated mental test ≤ 8) Yes No

Blood urea nitrogen > 7 mmol/L (19 mg/dL) Yes No

Respiratory rate ≥ 30 breaths/min Yes No

Low blood pressure (systolic < 90 mmHg or diastolic ≤ 60 mmHg) Yes No

Age ≥ 65 years Yes No

Results

CURB-65 Score

0

out of 5 — Low risk

Estimated 30-day mortality	0.6%
Risk category	Low risk
Suggested disposition	Consider outpatient treatment

What is the CURB-65 score?

CURB-65 is a clinical prediction tool used to assess the severity of community-acquired pneumonia (CAP) and guide decisions about whether a patient can be managed at home, on a general ward, or needs intensive care. It was derived from the British Thoracic Society research and is widely used internationally. This calculator is a decision-support aid and does not replace clinical judgment.

Each of the five CURB-65 criteria adds one point for a total score of 0 to 5.

How to use it

Answer Yes or No to each of the five criteria. Each "Yes" adds one point. The total ranges from 0 to 5. The calculator returns the score, the estimated 30-day mortality, a risk category, and a suggested disposition.

The five criteria explained

C – Confusion of new onset (or Abbreviated Mental Test score ≤ 8). U – blood Urea nitrogen greater than 7 mmol/L (about 19 mg/dL). R – Respiratory rate of 30 breaths per minute or more. B – low Blood pressure (systolic < 90 mmHg or diastolic ≤ 60 mmHg). 65 – Age 65 years or older. The score is simply the sum of points: $$\text{Score} = \text{C} + \text{U} + \text{R} + \text{B} + 65$$

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Higher CURB-65 scores correspond to higher 30-day mortality risk and more intensive care settings.

Worked example

An 80-year-old patient (1 point for age) presents with new confusion (1 point) and a respiratory rate of 32 (1 point). Urea is normal and blood pressure is fine. $$\text{Score} = 1 + 0 + 1 + 0 + 1 = 3$$ A score of 3 indicates high risk with roughly 14% 30-day mortality, so hospital admission and assessment for intensive care are recommended.

FAQ

What do the scores mean? 0–1: low risk (~0.6–2.7% mortality), consider outpatient care. 2: intermediate risk (~6.8%), consider a short hospital stay. 3–5: high risk (14–28%), hospitalize and assess for ICU.

Is CURB-65 the same as CRB-65? CRB-65 drops the urea (blood test) criterion, making it usable in primary care without labs; the maximum score is 4.

Does a low score guarantee safety? No. Always combine the score with clinical judgment, social circumstances, oxygen saturation, and comorbidities.