Calculate the Wells Score for pulmonary embolism probability. Summarizes the standard 7 criteria into low, moderate, or high pretest-probability bands.
The Wells Score for Pulmonary Embolism is one of the most widely used clinical prediction rules for estimating the pretest probability of PE. Developed by Philip Wells and colleagues, it combines 7 clinical criteria, including the subjective but important judgment that PE is the most likely diagnosis or equally likely to the alternatives.
The score can be read in either a three-level model (low, moderate, high) or a simplified two-level model (PE unlikely vs PE likely). Both approaches are used in modern PE pathways.
The value of the Wells score is that it turns a broad suspicion of PE into a more structured probability summary. That summary then sits beside D-dimer results, imaging findings, hemodynamic status, and the rest of the clinical picture rather than replacing them.
PE is often suspected but confirmed in only a minority of tested patients. The Wells score helps standardize that initial review so the workup can be discussed in a more consistent way across clinicians and settings.
This calculator is most useful as a risk-framing worksheet. It keeps the original criteria, total score, and the common cutoffs together without pretending the score alone decides imaging, anticoagulation, or disposition.
Wells Score for PE: Clinical signs/symptoms of DVT: 3.0 pts PE is #1 diagnosis or equally likely: 3.0 pts Heart rate ≥100 bpm: 1.5 pts Immobilization ≥3d or surgery ≤4 wks: 1.5 pts Previous DVT or PE: 1.5 pts Hemoptysis: 1.0 pt Malignancy (Tx ≤6mo or palliative): 1.0 pt Range: 0-12.5 Three-level: <2 Low | 2-6 Moderate | >6 High Two-level (simplified): ≤4 Unlikely | >4 Likely
Result: Wells Score 9.0 — High Probability (~67% PE prevalence)
DVT signs (3 pts) + PE most likely diagnosis (3 pts) + HR ≥100 (1.5 pts) + prior DVT/PE (1.5 pts) = 9.0 points. That places the case in the high-probability band, where imaging-first review is common, but the score still needs to be interpreted with the full PE assessment.
The Wells score works best as the pretest-probability layer in a larger PE pathway. It helps organize how strongly PE is being considered before D-dimer, imaging, and the broader clinical picture are fully integrated.
Lower-score bands are often paired with D-dimer-first pathways. Higher-score bands more often push the discussion toward imaging-first review. The exact sequence still depends on the local protocol, assay availability, pregnancy status, hemodynamic stability, and the rest of the case.
The "PE most likely" criterion is subjective, but it captures something important: the clinician's overall synthesis of the differential. That is one reason the Wells score remains widely used despite the existence of more purely rule-based alternatives.
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This calculator applies the original weighted Wells clinical prediction rule for pulmonary embolism by summing 3-point, 1.5-point, and 1-point criteria into the standard 0-12.5 score. It reports both the classic three-level model and the simplified two-level cutoff so the result can be used in the diagnostic pathways most commonly described in PE guidance.
The score is meant to structure pre-test probability before D-dimer or imaging, not to replace bedside assessment. The item stating that pulmonary embolism is the most likely diagnosis still depends on clinical judgment, and the rule should not be treated as fully validated for populations outside its main derivation and validation settings, such as pregnancy.
This is the most subjective criterion in the Wells score. It asks the clinician to integrate ALL available information — history, exam, ECG, chest X-ray, labs, alternative diagnoses — and judge whether PE is the most probable diagnosis. This criterion captures experienced clinical gestalt and is both the strength (improves discrimination) and limitation (introduces subjectivity) of the Wells score.
Both are validated. The two-level model (≤4 unlikely, >4 likely) is simpler and has been adopted by many guidelines (NICE, BTS). The three-level model provides more granularity and slightly different PE exclusion pathways. The two-level model combined with D-dimer is the most commonly used algorithm in emergency departments.
Yes. Large studies show that a low or unlikely Wells score combined with a negative D-dimer has a very high negative predictive value for PE. That is why D-dimer-first pathways are common in lower-score bands.
A simplified version assigns 1 point to each criterion (instead of variable weights). Cutoff: ≤1 unlikely, ≥2 likely. Some studies show comparable performance, and it is endorsed by several guidelines. However, the original weighted version remains more widely studied and used.
They are separate tools developed by the same group. The Wells PE score has 7 criteria and predicts pulmonary embolism probability. The Wells DVT score has 10 criteria and predicts deep vein thrombosis probability. They share some risk factors but are not interchangeable.
The Wells score has not been well validated in pregnancy. Pregnant patients have physiological changes (tachycardia, hypercoagulability) that may affect scoring. D-dimer is physiologically elevated in pregnancy. For pregnant patients with suspected PE, many guidelines recommend compression ultrasonography first, followed by V/Q scan if needed, reserving CTA as a second-line test.