Score pulmonary embolism probability with the published Wells criteria, in both the three-tier and the simplified two-tier forms.
Result
How to use this tool
Answer each of the seven Wells items yes or no.
Note that PE most likely is a clinical judgement, not a test.
Read both the three-tier and two-tier results.
Seek urgent assessment for breathlessness or chest pain regardless of score.
Formula & worked example
Leg DVT signs (3) plus PE as the most likely diagnosis (3) plus heart rate over 100 (1.5) gives 7.5 points: high probability, and PE likely on the two-tier rule.
Limitations — read this before you rely on it
Clinical prediction aid only; it never rules PE in or out alone and never delays emergency assessment. This tool is for education only and is not medical advice. Talk to a clinician about any result that worries you, and never change treatment because of a calculator result.
Frequently asked questions
A validated clinical prediction rule that estimates how likely pulmonary embolism is before testing.
No. It lowers probability; D-dimer and imaging decisions still follow local pathways and judgement.
When no alternative diagnosis explains the symptoms better than PE, judged by the assessing clinician.
No. The DVT Wells score is a different set of items for leg clots, not lung clots.
Only to understand urgency: suspected PE always needs same-day emergency assessment.