CURB-65 Score Calculator

Enter five clinical criteria to calculate the CURB-65 score and estimate 30-day mortality risk for community-acquired pneumonia.

Use the CURB-65 Score Calculator

For educational use only. Not a substitute for clinical judgment. All pneumonia management decisions must be made by qualified clinicians based on full patient assessment.

CURB-65 Criteria

Five clinical criteria — each present scores 1 point (maximum 5).

C

New acute confusion or disorientation — not pre-existing dementia or baseline cognitive impairment.

U

Scores 1 point if urea > 7 mmol/L (BUN > 19.6 mg/dL). Leave blank to select manually below.

mmol/L

Entering a numeric value overrides the manual selection above.

R

Scores 1 point if ≥ 30 breaths per minute.

breaths/min
B

Scores 1 point if systolic < 90 mmHg or diastolic ≤ 60 mmHg.

/ mmHg
65

Scores 1 point if the patient is 65 years of age or older.

Enter the clinical criteria
and click Calculate.

CURB-65 Criteria & Scoring Reference

Letter Criterion Threshold Points
C Confusion New acute confusion 1
U Urea > 7 mmol/L 1
R Respiratory Rate ≥ 30 breaths/min 1
B Blood Pressure Systolic < 90 or Diastolic ≤ 60 mmHg 1
65 Age ≥ 65 years 1
Total (maximum) 5

Score Interpretation & 30-Day Mortality

0 – 1
Low Risk
~1–3% 30-day mortality
Suitable for outpatient treatment with close follow-up in most cases.
2
Moderate Risk
~9% 30-day mortality
Short inpatient stay or closely supervised outpatient care warranted.
3 – 5
High Risk
~15–57% 30-day mortality
Hospital admission required; score 4–5 consider ICU-level care.

Summary

The CURB-65 score is a validated clinical prediction rule for assessing the severity of community-acquired pneumonia (CAP) in adults. Developed by the British Thoracic Society, it assigns one point each to five criteria: Confusion (new disorientation or altered mental status), Urea greater than 7 mmol/L (BUN > 19 mg/dL), Respiratory rate of 30 or more breaths per minute, Blood pressure with systolic below 90 mmHg or diastolic at or below 60 mmHg, and Age 65 years or older. Total scores range from 0 to 5. Scores of 0–1 indicate low risk (30-day mortality approximately 1–3%), suitable for outpatient treatment. A score of 2 indicates moderate risk (approximately 9%) and warrants short-stay inpatient care or close outpatient follow-up. Scores of 3–5 indicate high risk (approximately 15–40%) requiring hospital admission, with scores of 4–5 potentially warranting ICU-level care.

How it works

  1. Assess whether the patient has new confusion or disorientation (not pre-existing dementia).
  2. Enter the blood urea nitrogen (BUN) value in mmol/L or select whether it exceeds 7 mmol/L.
  3. Enter the respiratory rate; a rate of 30 or more per minute scores 1 point.
  4. Enter systolic and diastolic blood pressure; hypotension (systolic < 90 or diastolic ≤ 60) scores 1 point.
  5. Indicate whether the patient is aged 65 or older.
  6. The calculator totals the five binary criteria and displays the 30-day mortality risk category and hospitalization guidance.

Use cases

  • Determine outpatient versus inpatient management for adults with community-acquired pneumonia.
  • Triage patients presenting to the emergency department with suspected pneumonia.
  • Support clinical decision-making for ICU referral in severely ill patients.
  • Communicate pneumonia severity to consulting teams using a standardized score.
  • Facilitate early discharge planning for low-risk pneumonia patients.
  • Use as an educational tool in medical training for pneumonia management.
  • Apply as a complement to clinical judgment and chest imaging findings.
  • Track severity changes in patients with evolving pneumonia on serial assessments.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu