# Pneumonia Severity Index Calculator (PSI/PORT)

URL: https://speedycalculator.com/calculators/health/psi/
Last updated: 2026-10-30

> The PSI calculator scores the Pneumonia Severity Index (PORT score) from 20 variables – demographics, illnesses, examination and lab findings – to estimate 30-day mortality in community-acquired pneumonia and guide outpatient or inpatient care.

## Inputs

- Sex
- Age (years)
- Nursing home resident
- Neoplastic disease
- Liver disease
- Congestive heart failure
- Cerebrovascular disease
- Renal disease
- Altered mental status
- Respiratory rate ≥ 30/min
- Systolic BP < 90 mmHg
- Temperature < 35 °C or ≥ 40 °C
- Pulse ≥ 125/min
- Arterial pH < 7.35
- BUN ≥ 30 mg/dL (urea ≥ 11 mmol/L)
- Sodium < 130 mmol/L
- Glucose ≥ 250 mg/dL (14 mmol/L)
- Haematocrit < 30%
- PaO₂ < 60 mmHg or SaO₂ < 90%
- Pleural effusion

## Results

- PSI score
- PSI class and 30-day mortality

## Formula

```
Score = age (minus 10 for women) + points for each finding
Class I: under 50 with none of the comorbidities or examination findings
Class II ≤ 70 · III 71–90 · IV 91–130 · V > 130
```

## Explanation

The PSI was developed by Fine and colleagues in 1997 from over 50,000 patients. It is better than CURB-65 at identifying low-risk patients who can be safely treated at home. Classes I–III are low risk, IV moderate and V high.

### How to use the Pneumonia Severity Index Calculator

- **Sex**
- **Age**
- **Nursing home resident**
- **Neoplastic disease**
- **Liver disease**
- **Congestive heart failure**
- **Cerebrovascular disease**
- **Renal disease**
- **Altered mental status**
- **Respiratory rate ≥ 30/min**
- **Systolic BP < 90 mmHg**
- **Temperature < 35 °C or ≥ 40 °C**
- **Pulse ≥ 125/min**
- **Arterial pH < 7.35**
- **BUN ≥ 30 mg/dL (urea ≥ 11 mmol/L)**
- **Sodium < 130 mmol/L**
- **Glucose ≥ 250 mg/dL (14 mmol/L)**
- **Haematocrit < 30%**
- **PaO₂ < 60 mmHg or SaO₂ < 90%**
- **Pleural effusion**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Each answer carries the points shown in the published score. The calculator adds them up and maps the total to the published interpretation.

### Scoring table

ItemAnswers and pointsSexMale = 1; Female = 0Nursing home residentNo = 0; Yes = 10Neoplastic diseaseNo = 0; Yes = 30Liver diseaseNo = 0; Yes = 20Congestive heart failureNo = 0; Yes = 10Cerebrovascular diseaseNo = 0; Yes = 10Renal diseaseNo = 0; Yes = 10Altered mental statusNo = 0; Yes = 20Respiratory rate ≥ 30/minNo = 0; Yes = 20Systolic BP < 90 mmHgNo = 0; Yes = 20Temperature < 35 °C or ≥ 40 °CNo = 0; Yes = 15Pulse ≥ 125/minNo = 0; Yes = 10Arterial pH < 7.35No = 0; Yes = 30BUN ≥ 30 mg/dL (urea ≥ 11 mmol/L)No = 0; Yes = 20Sodium < 130 mmol/LNo = 0; Yes = 20Glucose ≥ 250 mg/dL (14 mmol/L)No = 0; Yes = 10Haematocrit < 30%No = 0; Yes = 10PaO₂ < 60 mmHg or SaO₂ < 90%No = 0; Yes = 10Pleural effusionNo = 0; Yes = 10

### Inputs explained

FieldWhat to enterSexChoose one: Male, FemaleAgeIn yearsNursing home residentChoose one: No, YesNeoplastic diseaseChoose one: No, YesLiver diseaseChoose one: No, YesCongestive heart failureChoose one: No, YesCerebrovascular diseaseChoose one: No, YesRenal diseaseChoose one: No, YesAltered mental statusChoose one: No, YesRespiratory rate ≥ 30/minChoose one: No, YesSystolic BP < 90 mmHgChoose one: No, YesTemperature < 35 °C or ≥ 40 °CChoose one: No, YesPulse ≥ 125/minChoose one: No, YesArterial pH < 7.35Choose one: No, YesBUN ≥ 30 mg/dL (urea ≥ 11 mmol/L)Choose one: No, YesSodium < 130 mmol/LChoose one: No, YesGlucose ≥ 250 mg/dL (14 mmol/L)Choose one: No, YesHaematocrit < 30%Choose one: No, YesPaO₂ < 60 mmHg or SaO₂ < 90%Choose one: No, YesPleural effusionChoose one: No, Yes
*Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.*

## Worked example

Inputs — Sex: Male; Age: 70 years; Nursing home resident: No; Neoplastic disease: No; Liver disease: No; Congestive heart failure: No; Cerebrovascular disease: No; Renal disease: No; Altered mental status: No; Respiratory rate ≥ 30/min: No; Systolic BP < 90 mmHg: No; Temperature < 35 °C or ≥ 40 °C: No; Pulse ≥ 125/min: No; Arterial pH < 7.35: No; BUN ≥ 30 mg/dL (urea ≥ 11 mmol/L): Yes; Sodium < 130 mmol/L: No; Glucose ≥ 250 mg/dL (14 mmol/L): No; Haematocrit < 30%: No; PaO₂ < 60 mmHg or SaO₂ < 90%: No; Pleural effusion: No.

Results — **PSI score = 90 points**; PSI class and 30-day mortality = Class III (0.9–2.8%) – outpatient or brief observation.

## Key terms

- **PORT**: Pneumonia Patient Outcomes Research Team.

## FAQ

**How is PSI different from CURB-65?**
PSI uses more variables and is better at identifying low-risk patients.

**Who is class I?**
Patients under 50 with no comorbidities and no abnormal vital signs or mental status.

**Does PSI include oxygen levels?**
Yes – but always admit patients with low oxygen regardless of class.


## Sources

- [Fine MJ et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med, 1997](https://pubmed.ncbi.nlm.nih.gov/8995086/)