Wood Units Calculator

Wood Units Calculator: Calculates Pulmonary Vascular Resistance (PVR) in Wood units (mmHg/L/min) and CGS units (dynes·sec/cm⁻⁵).

mPAP (mmHg)

PCWP (mmHg)

C.O. (L/min)

Guidelines & Evidence

Verified

Last Review: 2026-07-17

When to Use

Right heart catheterization interpretation

PAH classification and severity assessment

Lung transplant candidacy evaluation (PVR threshold)

Alternative to CGS units; older convention still used widely

Helps clinicians understand traditional reporting

How it Works

Formula

PVR (Wood units) = (mPAP − PCWP) / CO mPAP = mean pulmonary artery pressure (mmHg) PCWP = pulmonary capillary wedge pressure (mmHg) CO = cardiac output (L/min) Result in mmHg/L/min (Wood units) Conversion: 1 Wood unit = 80 dynes•sec•cm⁻⁵

PAH Severity (Wood Units)

PVR (Wood units)	Classification	Clinical Status
<3	Normal	Normal PVR
3–5	Mild elevation	Borderline PH
5–8	Moderate elevation	Mild-moderate PAH
>8	Severe elevation	Severe PAH
>12	Very severe	Advanced/transplant candidate

Last Comprehensive Review: 2026-07-17

Guidelines & Evidence

Verified

Last Review: 2026-07-17

When to Use

Right heart catheterization interpretation

PAH classification and severity assessment

Lung transplant candidacy evaluation (PVR threshold)

Alternative to CGS units; older convention still used widely

Helps clinicians understand traditional reporting

How it Works

Formula

PAH Severity (Wood Units)

PVR (Wood units)	Classification	Clinical Status
<3	Normal	Normal PVR
3–5	Mild elevation	Borderline PH
5–8	Moderate elevation	Mild-moderate PAH
>8	Severe elevation	Severe PAH
>12	Very severe	Advanced/transplant candidate

Last Comprehensive Review: 2026-07-17

Recent Journal Updates

British J Clinical PharmacologyJul 22, 2026

CHATD Questionnaire: Development, Validation and Evaluation of Child and Parent Attitudes Towards Deprescribing

Clinical Context

We think this has broad domain relevance to Wood Units Calculator.

British J HaematologyJul 22, 2026

Immunoglobulin replacement after chimeric antigen receptor T‐cell therapy in large B‐cell lymphoma with hypogammaglobulinaemia: Secondary Center for International Blood and Marrow Transplant Research analysis

Clinical Context

We think this has broad domain relevance to Wood Units Calculator.

JAMAJul 21, 2026

Correction to Primary Composite Outcome in a Trial of Transfusion Strategy

Clinical Context

We think this has broad domain relevance to Wood Units Calculator.

Wood Units Calculator

When to Use

When to Use

How it Works

Formula

PAH Severity (Wood Units)

Clinical Pearls

Thresholds & Decisions

When to Use

When to Use

How it Works

Formula

PAH Severity (Wood Units)

Clinical Pearls

Thresholds & Decisions

Recent Journal Updates

Wood Units Calculator

When to Use

When to Use

How it Works

Formula

PAH Severity (Wood Units)

Clinical Pearls

Thresholds & Decisions

When to Use

When to Use

How it Works

Formula

PAH Severity (Wood Units)

Clinical Pearls

Thresholds & Decisions

Recent Journal Updates