CURB-65 Calculator

Written by Great Medico

Updated September 24, 2026 •2 min read

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A lung or oxygenation value can be easy to misread when the formula is hidden. CURB-65 Calculator makes the calculation explicit, so you can see what the result represents—and what it does not.

What this calculator does

CURB-65 Calculator uses Confusion, Blood urea nitrogen, Respiratory rate, Systolic blood pressure, Diastolic blood pressure, and Age to produce the curb-65 score used by this calculator. It only uses the fields shown in this calculator; it does not silently add tests, diagnoses, symptoms, or clinical variables that are absent from the interface. CURB-65 numeric field flow; BUN >19 mg/dL corresponds to urea >7 mmol/L.

How to use it

Enter or select Confusion, Blood urea nitrogen, Respiratory rate, Systolic blood pressure, Diastolic blood pressure, and Age. Use measurements from the same respiratory assessment and confirm whether oxygen values are percentages, fractions, or pressures. If an input is unknown, it is better to leave the calculation unresolved than to invent a value.

How the calculation works

One point is assigned for confusion, BUN above the implemented threshold, respiratory rate at least 30/min, systolic pressure below 90 or diastolic pressure at or below 60 mmHg, and age 65 or older. The five components are summed for the CURB-65 score.

Example

Using the calculator’s prefilled demonstration values, the primary output is 0 points, labeled “CURB-65 score”; Maximum is 5. That sample is useful for checking the calculation path, but real interpretation should use verified measurements from the same clinical or study context.

How to interpret the result

Read curb-65 score in the context of the pulmonary measurement or scoring system used. Trends, measurement quality, oxygen/ventilator settings, and the disease being evaluated usually matter more than an isolated decimal value.

Limitations and notes

Respiratory measurements depend on technique, calibration, oxygen/ventilator settings, altitude, timing, and the patient population in which a rule was validated. A single calculated value should be interpreted with symptoms, examination, serial measurements, imaging, and the clinical question that prompted the test.