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.