Wells Criteria for PE Calculator

inputs

Clinical signs/symptoms of DVT (leg swelling + pain with palpation)
3 points

PE is the most likely diagnosis (or equally likely)
3 points

Heart rate >100 bpm
1.5 points

Immobilisation ≥3 days or surgery within 4 weeks
1.5 points

Previous DVT or PE
1.5 points

Haemoptysis
1 point

Active malignancy (treatment within 6 months or palliative)
1 point

✓ when to use

Use in adult patients presenting with symptoms suggestive of PE (dyspnoea, pleuritic chest pain, tachycardia, haemoptysis). The score determines the diagnostic strategy: low probability → PERC or D-dimer → if negative, exclude PE; moderate → D-dimer → if positive, CTPA; high → proceed directly to CTPA.

✗ when not to use

The 'PE most likely diagnosis' criterion (3 points) is subjective and has significant inter-rater variability. Not validated in pregnancy (where D-dimer is physiologically elevated and CTPA has radiation considerations), hospitalised patients, or children. The original three-level model and the simplified two-level model (≤4 vs >4) are both in use — know which version your pathway uses.

clinical pearls

The two-level Wells model (PE unlikely ≤4, PE likely >4) is simpler and increasingly preferred in clinical pathways, including by NICE. Know which version your institution uses.
'PE is the most likely diagnosis' (3 points) is simultaneously the highest-weighted criterion and the most subjective. It essentially asks for your clinical gestalt — which makes the Wells score partially circular. Document your reasoning.
In patients ≥50 years, consider the age-adjusted D-dimer threshold (age × 10 µg/L) rather than the standard 500 µg/L. This reduces false-positive rates and unnecessary CTPA without compromising safety.
The Wells PE and Wells DVT scores are different tools with different criteria and should not be confused. Both can be applied in the same patient if both PE and DVT are suspected.
In pregnant patients, the Wells score is not validated, and D-dimer is not useful (physiologically elevated). Most guidelines recommend proceeding directly to imaging (compression ultrasound of legs first, then CTPA or V/Q if DVT not found) based on clinical suspicion.

✓ when to use

✗ when not to use

clinical pearls

The two-level Wells model (PE unlikely ≤4, PE likely >4) is simpler and increasingly preferred in clinical pathways, including by NICE. Know which version your institution uses.
'PE is the most likely diagnosis' (3 points) is simultaneously the highest-weighted criterion and the most subjective. It essentially asks for your clinical gestalt — which makes the Wells score partially circular. Document your reasoning.
In patients ≥50 years, consider the age-adjusted D-dimer threshold (age × 10 µg/L) rather than the standard 500 µg/L. This reduces false-positive rates and unnecessary CTPA without compromising safety.
The Wells PE and Wells DVT scores are different tools with different criteria and should not be confused. Both can be applied in the same patient if both PE and DVT are suspected.
In pregnant patients, the Wells score is not validated, and D-dimer is not useful (physiologically elevated). Most guidelines recommend proceeding directly to imaging (compression ultrasound of legs first, then CTPA or V/Q if DVT not found) based on clinical suspicion.

Wells Criteria for PE

inputs

✓ when to use

✗ when not to use

clinical pearls

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