CURB-65 / PSI Calculator

Calculate CURB-65 severity score for community acquired pneumonia.

About CURB-65 / PSI Calculator

Each of the five criteria contributes one point, and mortality rises steeply above a score of two. The score informs the site-of-care decision within local protocols rather than determining it. Severity scores can underestimate risk in younger patients with few comorbidities, so clinical judgement overrides the score in both directions.

Formula

CURB-65 / PSI

One point each for confusion, urea over 7, respiratory rate 30 or more, low BP and age 65 or over

CURB-65: A five point severity score for community acquired pneumonia
30-day mortality: Published rates associated with each score band

Worked example

With the default values below, CURB-65 / PSI Calculator returns CURB-65 Score of 2. Change any input above and every figure here is recalculated in your browser.

Inputs used

New confusionone of Yes, No: No
Blood ureaminimum 0 mmol/L: 8.2 mmol/L
Respiratory rateaccepts 4–80 breaths/min: 26 breaths/min
Systolic blood pressureaccepts 40–250 mmHg: 105 mmHg
Diastolic blood pressureaccepts 20–150 mmHg: 68 mmHg
Ageaccepts 18–110 years: 68 years

Results

CURB-65 Score: 2 /5
Published 30-Day Mortality: 6.80%
Risk Category: Moderate severity
Criteria Met: Confusion No, urea Yes, respiratory rate No, blood pressure No, age Yes
Age 65 or Over: Yes

Step by step

1Values used
2CURB-65 / PSI
3CURB-65 Score= 2 /5
4Published 30-Day Mortality= 6.80
5Risk Category= Moderate severity
6Criteria Met= Confusion No, urea Yes, respiratory rate No, blood pressure No, age Yes
7Age 65 or Over= Yes

Assumptions and limits

The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
This reproduces a published formula for educational and reference use only. It is not a diagnostic tool, does not account for individual clinical context, and must not be used to make or change treatment decisions. Clinical assessment by a qualified healthcare professional is always required. Pneumonia can deteriorate rapidly. If you or someone else has difficulty breathing, confusion or chest pain, seek urgent medical care. This score is a clinical decision aid, not a triage substitute.
This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

This reproduces a published formula for educational and reference use only. It is not a diagnostic tool, does not account for individual clinical context, and must not be used to make or change treatment decisions. Clinical assessment by a qualified healthcare professional is always required. Pneumonia can deteriorate rapidly. If you or someone else has difficulty breathing, confusion or chest pain, seek urgent medical care. This score is a clinical decision aid, not a triage substitute.

Frequently Asked Questions

How is CURB-65 / PSI calculated?

One point each for confusion, urea over 7, respiratory rate 30 or more, low BP and age 65 or over Each of the five criteria contributes one point, and mortality rises steeply above a score of two. The score informs the site-of-care decision within local protocols rather than determining it.

Why does CURB-65 / PSI matter?

Severity scores can underestimate risk in younger patients with few comorbidities, so clinical judgement overrides the score in both directions.

What values do I need to enter?

This calculator takes 6 inputs: New confusion, Blood urea, Respiratory rate, Systolic blood pressure, Diastolic blood pressure, Age. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.