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Wells Score for PE Calculator

The Wells score for pulmonary embolism (PE) turns bedside findings into a pre-test probability estimate. It is used before testing: in a patient with a low clinical probability, a negative D-dimer can safely exclude PE without imaging in validated pathways; when PE is likely, imaging is the next step regardless.

Formula: Sum the points for each feature present. Two features carry 3 points — clinical signs of DVT, and PE judged the most likely diagnosis — the rest 1 or 1.5.

Enter the values or tick the options above — the result updates automatically.

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How to interpret the result

ModelScoreGrouping
Two-tier4 or belowPE unlikely
Two-tierAbove 4PE likely
Three-tierUnder 2Low probability
Three-tier2–6Moderate probability
Three-tierAbove 6High probability

The single most subjective item — "PE is the most likely diagnosis" — is also one of the heaviest at 3 points. The score structures that judgment; it does not remove it.

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Frequently asked questions

What Wells score means PE is "likely"?

In the two-tier model, a score above 4 is "PE likely" and 4 or below is "PE unlikely". The older three-tier model groups under 2 as low, 2–6 as moderate, and above 6 as high probability.

Why does the Wells score matter before a D-dimer?

D-dimer is only useful for excluding PE when the clinical probability is low or "unlikely" — a negative result there makes PE very unlikely. In a "PE likely" patient a negative D-dimer does not safely exclude PE, so imaging is used instead.

Is the Wells score used for DVT as well?

There is a separate Wells score for deep vein thrombosis with different criteria and a −2 item for an alternative diagnosis. This page is the pulmonary embolism version.

Educational use only. This calculator is an aid to learning and does not replace clinical judgment, local reference ranges, or specialist advice. Always interpret a result alongside the patient, the full laboratory picture, and your laboratory's own reference ranges.