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CURB-65 Score Calculator

Estimate 30-day mortality risk in community-acquired pneumonia.

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Same equations the textbooks use — just way less awkward. Pop in your stats and I'll tell you what the number actually means for you.

Try a scenario

Click to load — tweak from there.

Inputs

Result

CURB-65 score

0

Estimated 30-day mortality risk

Low risk (~0.7% mortality)

Disposition guidance

Outpatient treatment often appropriate

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How to use this

  1. 1Enter new confusion.
  2. 2Enter bun (mg/dL).
  3. 3Enter respiratory rate (/min).
  4. 4Enter systolic bp (mmHg).
  5. 5Enter diastolic bp (mmHg).
  6. 6Enter age (years).
  7. 7Read your curb-65 score on the right — it updates as you type.
  8. 8Hit Share to keep the scenario or send it to someone.

About this calculator

CURB-65 scores community-acquired pneumonia severity using five criteria — Confusion, Urea (BUN) over 19 mg/dL (7 mmol/L), Respiratory rate 30/min or higher, Blood pressure (systolic under 90 or diastolic 60 or below), and age 65 or older — each worth one point, to estimate 30-day mortality and guide the outpatient-versus-inpatient decision. A score of 0-1 suggests low mortality risk and often supports outpatient treatment; a score of 2 suggests consideration of short inpatient stay or closely supervised outpatient care; a score of 3 or higher suggests severe pneumonia warranting hospitalization, with 4-5 often prompting ICU-level consideration. It is a decision-support aid, not the sole determinant — social factors (ability to take oral antibiotics, follow-up access, home support), oxygen saturation, and comorbidities that CURB-65 does not capture frequently change the actual disposition decision in real practice, and CRB-65 (dropping urea) is used when a BUN result is not immediately available. This tool is for education and workflow support only — not medical advice. Always verify results with a clinician and use clinical judgment alongside your institution's protocols.

Formula1 point each: Confusion, Urea/BUN >19 mg/dL, RR ≥30, SBP <90 or DBP ≤60, Age ≥65.

Worked example

Using the values the calculator loads with:

Inputs

  • New confusion: No
  • BUN: 15 mg/dL
  • Respiratory rate: 22 /min
  • Systolic BP: 110 mmHg
  • Diastolic BP: 70 mmHg
  • Age: 58 years

Results

  • CURB-65 score: 0
  • Estimated 30-day mortality risk: Low risk (~0.7% mortality)
  • Disposition guidance: Outpatient treatment often appropriate

What each field means

Inputs

New confusion
Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
BUN (mg/dL)
The bun used in the calculation, measured in mg/dL. Starts at 15 mg/dL so you have a working example on load. Accepted range: 2–150 mg/dL.
Respiratory rate (/min)
The respiratory rate used in the calculation, measured in /min. Starts at 22 /min so you have a working example on load. Accepted range: 8–60 /min.
Systolic BP (mmHg)
The systolic bp used in the calculation, measured in mmHg. Starts at 110 mmHg so you have a working example on load. Accepted range: 40–250 mmHg.
Diastolic BP (mmHg)
The diastolic bp used in the calculation, measured in mmHg. Starts at 70 mmHg so you have a working example on load. Accepted range: 20–150 mmHg.
Age (years)
The age used in the calculation, measured in years. Starts at 58 years so you have a working example on load. Accepted range: 1–110 years.

Results

CURB-65 score
Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Estimated 30-day mortality risk
Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
Disposition guidance
Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.

FAQ

What's the difference between CURB-65 and CRB-65?

CRB-65 drops the urea (BUN) criterion, making it usable at the bedside or in outpatient settings without immediate lab access, at the cost of slightly less discriminatory power. It uses the same 0-4 scoring logic across the remaining four criteria and similar disposition thresholds.

Should the score alone decide admission?

No. CURB-65 is a decision-support aid that should be combined with clinical judgment, oxygen saturation, comorbidities, ability to tolerate oral intake, home support, and follow-up access. Many clinicians hospitalize low-CURB-65 patients who lack safe outpatient support, and treat some higher-score patients as outpatients when the elevated point is due to age alone in an otherwise well-appearing patient.

Why is age 65 a full point regardless of other factors?

Age itself is an independent risk factor for pneumonia mortality, partly reflecting reduced physiologic reserve and higher comorbidity burden, even when other vital signs look reassuring. This is also why the score can be misleading in a robust 66-year-old versus a frail 66-year-old — clinical context still matters.

What CURB-65 score typically triggers ICU consideration?

Scores of 4-5 are associated with high 30-day mortality and often prompt evaluation for ICU-level care, though ICU admission should also be guided by criteria like severe hypoxemia, need for vasopressors, or respiratory failure, not the CURB-65 score in isolation.

Accuracy and limitations

  • Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.
  • Results do not account for medical conditions, medication, or pregnancy.
  • Use this as a directional reference, not a diagnosis — talk to a clinician before acting on it.

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Cite this calculator

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APA
RevenueLab. (2026). CURB-65 Pneumonia Severity Score. Retrieved from https://www.revenuelab.fyi/toolbox/curb-65-score
HTML
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/curb-65-score" target="_blank" rel="noopener">CURB-65 Pneumonia Severity Score — RevenueLab</a> (2026).</p>
Markdown
Source: [CURB-65 Pneumonia Severity Score — RevenueLab](https://www.revenuelab.fyi/toolbox/curb-65-score) (2026).
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