CURB-65 Score Calculator for Pneumonia
Assess the severity of community-acquired pneumonia and guide the admit-or-treat-at-home decision with the CURB-65 score. Five findings each add one point — new Confusion, raised Urea, high Respiratory rate, low Blood pressure and age 65 or over — for a total of 0 to 5. Tick those that apply to get the score, the approximate 30-day mortality and the suggested care setting.
About CURB-65
CURB-65 risk-stratifies adults with community-acquired pneumonia to help decide between outpatient and inpatient care. Each of the five features scores one point. Source: Lim WS et al., “Defining community acquired pneumonia severity on presentation to hospital,” Thorax 2003;58(5):377–382.
Frequently asked questions
What do the CURB-65 letters stand for?
CURB-65 stands for Confusion (new disorientation); Urea over 7 mmol/L (blood urea nitrogen over about 19 mg/dL); Respiratory rate 30 breaths per minute or more; Blood pressure that is low (systolic under 90 mmHg or diastolic 60 mmHg or below); and age 65 or over. Each present feature adds one point, giving a score from 0 to 5. The name is the mnemonic itself — C, U, R, B and 65 — and every item carries equal weight. All five can be established from a history, one set of observations and a single blood test.
How does the score guide treatment?
As a general guide: 0–1 is low risk and often suitable for outpatient treatment; 2 is intermediate and may warrant a short hospital stay or closely supervised outpatient care; and 3–5 is high risk and usually means admission, with intensive-care assessment considered at 4–5. The score supports, but does not replace, clinical judgement and social circumstances. This calculator shows the matching care setting for each total and adds an intensive-care prompt at 4–5. It says nothing about which antibiotic to give; that comes from local community-acquired pneumonia guidance.
What is the 30-day mortality at each score?
In the original derivation the approximate 30-day mortality rose with the score: about 0.6% at 0, 2.7% at 1, 6.8% at 2, 14% at 3, and around 28% at 4–5. These figures come from hospital cohorts and are approximate; local populations differ, so use the risk band rather than the exact percentage. The calculator prints the same figure beside the score, labelled as approximate. Scores of 4 and 5 were pooled in the derivation, which is why both show about 28%.
What is CRB-65?
CRB-65 is a simplified version that drops the urea (blood test) and uses only Confusion, Respiratory rate, Blood pressure and age 65+, scored 0 to 4. It is useful in primary care or wherever a blood test is not immediately available. This calculator uses the full CURB-65, which needs the urea result.
When should it not be relied on?
CURB-65 is validated for community-acquired pneumonia in adults, not for hospital-acquired pneumonia, immunocompromised patients or children. It can underestimate risk in younger patients with few points but significant illness, and does not account for oxygenation or comorbidity on its own. This is an educational reference, not medical advice.
This is a reference tool, not a diagnosis or medical advice. Results depend on the laboratory, assay and clinical context, and reference intervals vary between labs and by age and sex — always read your result against the range printed on your own report and discuss it with a qualified healthcare professional.
More medical calculators
eGFRCreatinine ClearanceBody Surface AreaCorrected CalciumAnion GapA1C to eAGHOMA-IRQUICKIGMICholesterol RatioMean Arterial PressureQTcWaist-to-Hip RatioWaist-to-Height RatioLean Body MassPack-YearVO₂ MaxMELD ScoreFramingham RiskASCVD RiskCHA₂DS₂-VAScHAS-BLEDWells DVTWells PEMELD 3.0PREVENT RiskCHA₂DS₂-VAGeneva ScorePERC RuleChild-PughGlasgow Coma (GCS)FIB-4 IndexCorrected SodiumSerum OsmolalityAPRIFatty Liver IndexNAFLD Fibrosis ScoreCentor ScoreFeNaqSOFALVH (ECG)ESR (VSH)Thymol TurbidityMaddrey's DFA-a GradientNEWS2ANCWinters' FormulaShock IndexAlvarado ScoreReticulocyte IndexFree Water DeficitPadua ScoreGlasgow-BlatchfordCIWA-ArMMEMaintenance FluidsBishop ScoreVancomycinSteroid ConversionHEART ScorePediatric DoseSOFA ScoreTransferrin SaturationSF Syncope RuleParkland FormulaInsulin CorrectionCaprini ScoreNIHSSPSI / PORT Lab unit converters →