Wells Score for Pulmonary Embolism Calculator

The Wells score for pulmonary embolism is a clinical prediction rule derived by Wells and colleagues in 2000. It turns seven bedside findings into a single number that estimates how likely PE is before any imaging, a pretest probability. The tool above adds the point value of every criterion you tick and applies the published cut-offs. Nothing is uploaded; the calculation runs entirely in your browser.

The seven criteria and their points are fixed by the original paper:

• Clinical signs and symptoms of DVT, 3.0
• PE is the most likely diagnosis, 3.0
• Heart rate > 100 bpm, 1.5
• Immobilisation ≥ 3 days or surgery < 4 weeks, 1.5
• Previous objectively diagnosed DVT or PE, 1.5
• Haemoptysis, 1.0
• Active malignancy, 1.0

The maximum possible total is 12.5. Two interpretation models then read that total:

Three-tier (Wells et al., 2000). A score below 2 is low probability, 2 to 6 inclusive is moderate, and above 6 is high. These bands mirror the PE rates seen in the derivation cohort, where low-probability patients had roughly a 1–4% chance of PE and high-probability patients around 40–67%.

Two-tier / dichotomised (Christopher Study, 2006; NICE NG158). The same total is collapsed into two groups: a score of 4 or below is PE unlikely and above 4 is PE likely. This is the model most modern guidelines use to drive testing, unlikely patients get a D-dimer (a negative result safely excludes PE), while likely patients go straight to CT pulmonary angiography. Because the boundaries differ, a total of exactly 4 is moderate on the three-tier model yet unlikely on the two-tier model, the tool shows both so the disagreement is explicit rather than hidden.

To keep the arithmetic trustworthy, the underlying module computes the total two independent ways, once by summing the criteria table and once from the literal point formula, and only shows the “cross-checked” badge when the two agree to the point. Every cut-off is a fixed value from the cited literature; there is no rounding, interpolation, or opinion in the scoring.

• Wells PS, et al. Derivation of a simple clinical model to categorize patients probability of PE. Thromb Haemost. 2000;83(3):416–420
• Christopher Study Investigators. Managing suspected PE using clinical probability, D-dimer and CT. JAMA. 2006;295(2):172–179
• NICE guideline NG158: Venous thromboembolic diseases: diagnosis, management and thrombophilia testing (2020, updated 2023)
• 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism. Eur Heart J. 2020;41(4):543–603

The seven criteria, point values and both sets of cut-offs on this page were last cross-checked against the sources above on 2026-07-12. This is an educational reference, not a medical device, and it stores no patient data.