CURB-65 Pneumonia Score Calculator
CURB-65 pneumonia score with mortality bands and care setting.
What it does
Pneumonia triage turns on one decision: home, ward, or intensive care. CURB-65 answers it with five bedside facts that any clinic can gather in minutes. The British Thoracic Society and NICE both endorse it, and validation cohorts across continents hold its numbers steady.
The tool above scores the five criteria at once. Enter confusion, urea, breathing rate, pressures, and age. It returns the 0 to 5 total, the 30-day mortality band, and the care setting. Defaults describe a 70 year old at 8, 32, and 110 over 70, so the page opens solved at 3 with 14.0 percent.
Each letter earns its point the same way. New confusion, urea above 7, breathing at 30 plus, pressure under 90 systolic or 60 diastolic, and age past 65 each add one. No weighting, no calculator tricks: three or more means severe pneumonia until proven otherwise.
Mortality climbs steeply, not linearly. Zero carries 0.6 percent while five carries 27.8, nearly fifty times higher. That curve is why a score of 2 already buys admission or tight supervision rather than reassurance.
Use the table to fix bands in memory, then score the patient. Blood tests missing? The CRB variant drops urea and runs 0 to 4; judgment overrules every version.
How to use
- Record new confusion yes or no.
- Enter urea in mmol/L (BUN x 0.357).
- Enter breathing rate per minute.
- Enter systolic and diastolic pressure.
- Enter age.
- Read score, mortality, and care setting.
Formula
- C
- New confusion or disorientation: 1 if yes.
- U
- Urea in mmol/L; 1 point above 7.
- R
- Breaths per minute; 1 point at 30 or more.
- B
- Systolic under 90 or diastolic 60 or under: 1 point.
- 65
- 1 point at age 65 or older.
Confusion: new disorientation. Urea above 7 mmol/L (BUN above 20 mg/dL). Breathing rate 30 or more per minute. Blood pressure below 90 systolic or 60 or less diastolic. Age 65 or older. Mortality bands are weighted validation averages.
Worked example
Example: score 3, high risk
Age 70, no confusion, urea 8, breathing 32, pressure 110/70. Score it.
- Confusion: no is 0 points.
- Urea 8 exceeds 7, so 1 point.
- Breathing 32 reaches 30, so 1 point.
- Pressure 110 over 70 is safe, so 0 points.
- Age 70 reaches 65, so 1 point.
- Total 3: 14.0% mortality, hospitalize with ICU considered.
Reference table
| Score | Mortality | Setting |
|---|---|---|
| 0 | 0.6% | Home treatment considered |
| 1 | 2.7% | Home treatment considered |
| 2 | 6.8% | Short admission or close supervision |
| 3 (worked) | 14.0% | Hospitalize, consider ICU |
| 4 to 5 | 27.8% | Hospitalize, consider ICU |
Limits
- Adults with community pneumonia, not children.
- Needs clinical judgment alongside.
- Urea needs a blood draw; use CRB without.
- Bands are averages across cohorts.
Common mistakes
- Using BUN 7 as the cutoff instead of urea 7.
- Skipping confusion in quiet patients.
- Sending 2s home without supervision.
- Treating the score as a diagnosis.
- Forgetting age counts a full point.
Try it yourself
Quick checks. Answers sit tucked under each question.
40 year old, clear, urea 5, breathing 18, 120/80?
No points anywhere: 0 with 0.6% mortality, home treatment considered.
80 year old, confused, urea 12, breathing 34, 85/55?
All five met: 5 with 27.8% mortality, hospitalize with ICU considered.
BUN 20 mg/dL in urea units?
BUN 20 x 0.357 = 7.1 mmol/L, just over 7, so 1 urea point.
Questions
What does CURB-65 stand for?
Confusion, Urea over 7, breathing rate 30 plus, low Blood pressure, age 65 plus. One point each, total 0 to 5.
My lab reports BUN instead?
BUN over 20 mg/dL matches urea over 7 mmol/L. Multiply BUN by 0.357 to convert.
What are the death rates?
0: 0.6%, 1: 2.7%, 2: 6.8%, 3: 14.0%, 4 to 5: 27.8%. Weighted averages from validation studies.
Where should each score go?
Scores 0 to 1 suit home care, 2 needs admission or close supervision, 3 plus needs hospital with ICU considered. Judgment overrules always.
What is CRB-65?
CRB-65 drops urea for settings without blood tests, scoring 0 to 4. It runs slightly hotter per point.
Does it replace the pneumonia severity index?
No. PSI adds age, illnesses, and labs for finer sorting. CURB-65 wins on speed; PSI wins on detail.
Sources
- BMJ Best Practice: community-acquired pneumonia CURB-65 criteria
- NICE NG250: pneumonia diagnosis and management