Wells Score for PE Calculator
Wells score for pulmonary embolism using seven weighted criteria and two-level risk.
What it does
The Wells score for pulmonary embolism is a seven-item clinical prediction rule. It estimates how likely PE is before D-dimer testing or imaging.
Each item carries a fixed weight. Signs of DVT and an alternative diagnosis that is less likely than PE each add 3 points. Heart rate above 100, recent immobilization or surgery, previous DVT or PE each add 1.5 points. Hemoptysis and active malignancy each add 1 point.
The two-level interpretation is the most widely used version. A score above 4 places the patient in the PE likely group, where imaging is usually the next step. A score of 4 or less places the patient in the PE unlikely group, where a negative D-dimer can often exclude PE.
The defaults include an alternative diagnosis less likely than PE and a heart rate above 100, for a score of 4.5. That is in the PE likely group, so the tool suggests CT pulmonary angiography or ventilation-perfusion imaging per the local pathway.
How to use
- Review the seven criteria and select Yes only when the finding is clearly present.
- Count DVT signs only when leg swelling and deep vein tenderness are present.
- Use clinician judgment for the alternative diagnosis item; it carries the same weight as DVT signs.
- Enter heart rate, immobilization, prior VTE, hemoptysis, and malignancy status.
- Press Calculate to see the weighted score and the two-level risk group.
- Follow the local PE pathway; the score does not replace clinical assessment or imaging decisions.
Formula
- DVT signs
- 3 points for leg swelling and pain along the deep veins.
- Alternative diagnosis
- 3 points when PE is more likely than an alternative diagnosis.
- Heart rate
- 1.5 points when above 100/min.
- Immobilization or surgery
- 1.5 points for at least 3 days immobilized or surgery within 4 weeks.
- Prior VTE
- 1.5 points for previous DVT or PE.
- Hemoptysis
- 1 point.
- Malignancy
- 1 point for active cancer.
Add the points for every criterion that is present. The two-level interpretation uses more than 4 points for PE likely and 4 or less for PE unlikely. The original three-level version is not used on this page because the two-level pathway is simpler and better validated for current clinical use. The score is a pretest probability tool, not a diagnostic test.
Worked example
Example: alternative diagnosis less likely plus tachycardia
Defaults: DVT signs No, alternative diagnosis less likely Yes, heart rate above 100 Yes, immobilization No, prior VTE No, hemoptysis No, active malignancy No.
- Alternative diagnosis less likely than PE: 3 points.
- Heart rate above 100/min: 1.5 points.
- All other criteria are No: 0 points.
- Add the points: 3 + 1.5 = 4.5.
- The score is above 4, so the two-level group is PE likely.
- The tool suggests CT pulmonary angiography or V/Q imaging per the local pathway.
Reference table
| Criterion | Points |
|---|---|
| Clinical signs of DVT | 3 |
| PE more likely than an alternative diagnosis | 3 |
| Heart rate above 100/min | 1.5 |
| Immobilization at least 3 days or surgery within 4 weeks | 1.5 |
| Previous DVT or PE | 1.5 |
| Hemoptysis | 1 |
| Active malignancy | 1 |
Limits
- The score estimates pretest probability and cannot confirm or exclude PE by itself.
- It performs best when used with a validated D-dimer or imaging pathway.
- Pregnancy, recent anticoagulation, and unstable patients need individualized assessment.
- The alternative diagnosis item depends on clinician judgment and can vary between assessors.
Common mistakes
- Using the three-level interpretation when the local pathway uses the two-level version.
- Counting a score of exactly 4 as PE likely instead of PE unlikely.
- Selecting DVT signs for leg pain without swelling or deep vein tenderness.
- Ordering imaging based on the score alone without considering the full clinical picture.
- Applying the score to a patient who is too unstable for a diagnostic pathway.
Try it yourself
Quick checks. Answers sit tucked under each question.
A patient has DVT signs, tachycardia, and prior PE. What is the Wells score?
6.0. DVT signs add 3, tachycardia adds 1.5, and prior PE adds 1.5. The result is above 4, so PE is likely.
A patient has hemoptysis and active malignancy only. What is the Wells score?
2.0. Hemoptysis adds 1 and malignancy adds 1. The score is 4 or less, so PE is unlikely.
A patient has no criteria at all. What is the interpretation?
0 points, PE unlikely. A negative D-dimer can help exclude PE in the right clinical setting.
Questions
What is a normal Wells score?
There is no normal value. The score is grouped into PE unlikely at 4 or less and PE likely above 4.
Why is 4.5 considered PE likely?
The two-level rule uses more than 4 points for the likely group. A score of 4.5 is above that boundary, so it falls in the likely group.
Can the Wells score diagnose PE?
No. It estimates pretest probability and guides the choice of D-dimer testing or imaging. Diagnosis requires a positive test or imaging finding.
Does a low Wells score mean no PE?
No. A score of 4 or less makes PE less likely, but exclusion usually requires a negative D-dimer or imaging, depending on the pathway.
What counts as active malignancy?
Cancer treated within the past 6 months or receiving palliative treatment. A history of cured cancer does not count unless it is active.
Can I use this score in pregnancy?
Pregnancy requires a dedicated pathway. The Wells score can inform assessment, but D-dimer thresholds and imaging choices differ.
Sources
- Wells criteria for pulmonary embolism, StatPearls
- Wells score validation and diagnostic pathway review
- Wells et al., derivation of the PE prediction rule