Wells score calculator for DVT and PE
For healthcare professionals and students. Check results against your local protocols and clinical judgement; this tool does not give medical advice.
This Wells score calculator gives the pre-test probability of deep-vein thrombosis or pulmonary embolism using the Wells criteria exactly as published. Switch between DVT and PE, tick the findings that apply, and it shows the score with both the two-level (likely/unlikely) and the three-level (low/moderate/high) interpretation, the criteria counted and the numbers the original studies reported.
It is aimed at medical and nursing students, emergency and acute medicine teams and anyone revising the “Wells criteria” for exams. It does not choose a test or a treatment for you; it keeps the arithmetic and the cut-offs honest. Nothing leaves your browser.
How to use the Wells Score Calculator (DVT and PE)
- Choose DVT (leg) or Pulmonary embolism.
- Tick every criterion that is present. For DVT with symptoms in both legs, score the more symptomatic leg.
- For DVT, tick “alternative diagnosis at least as likely” when it applies — it subtracts 2 points.
- Read the score and the two- and three-level categories, and check the criteria listed under the result.
- Copy the result into your notes and follow your local diagnostic pathway for the next test.
Wells Score Calculator (DVT and PE) features
DVT and PE in one place
Both Wells rules with their own point values, including the 1.5-point PE items and the −2 DVT item.
Two- and three-level bands
Likely/unlikely and low/moderate/high shown together, each with the cut-off that produced it.
Faithful to the papers
The 1997 DVT model excludes “previously documented DVT”, which was added in 2003; the tool shows both totals.
Published figures
DVT prevalence by category from the 1997 study and PE rates from the 2000 derivation set, labelled with their source.
Copyable summary
Score, categories and the criteria present, in one line for notes or handover.
Wells criteria for DVT
The original model (Wells PS et al., Lancet 1997;350(9094):1795–1798) scored nine items, with −2 for an alternative diagnosis, and grouped patients as low (0 or less), moderate (1–2) or high (3 or more). Among 593 outpatients, DVT was found in 3%, 17% and 75% of these groups.
In 2003 (Wells PS et al., N Engl J Med 2003;349(13):1227–1235) a tenth item, previously documented DVT, was added and patients were classed as likely (2 or more) or unlikely (1 or less). The trial concluded that DVT can be ruled out in a patient judged clinically unlikely who has a negative D-dimer, without ultrasound.
| DVT criterion | Points |
|---|---|
| Active cancer (treatment ongoing, within the previous 6 months, or palliative) | +1 |
| Paralysis, paresis or recent plaster immobilisation of a lower limb | +1 |
| Recently bedridden for 3 days or more, or major surgery within 12 weeks needing general or regional anaesthesia | +1 |
| Localised tenderness along the distribution of the deep venous system | +1 |
| Entire leg swollen | +1 |
| Calf swelling at least 3 cm larger than the other side (measured 10 cm below the tibial tuberosity) | +1 |
| Pitting oedema confined to the symptomatic leg | +1 |
| Collateral superficial veins (non-varicose) | +1 |
| Previously documented DVT | +1 |
| An alternative diagnosis is at least as likely as DVT | −2 |
Wells criteria for pulmonary embolism
The PE rule (Wells PS et al., Thromb Haemost 2000;83(3):416–420) was derived from 40 candidate variables. Its three-level version is low (under 2), moderate (2 to 6) and high (over 6); the two-level version is PE unlikely (4 or less) and PE likely (over 4). In the derivation set 7.8% of “unlikely” patients had PE, falling to 2.2% when their SimpliRED D-dimer was negative — a combination present in 46% of patients.
| PE criterion | Points |
|---|---|
| Clinical signs and symptoms of DVT (at minimum leg swelling and pain on palpation of the deep veins) | +3 |
| An alternative diagnosis is less likely than PE | +3 |
| Heart rate over 100 beats per minute | +1.5 |
| Immobilisation for 3 days or more, or surgery in the previous 4 weeks | +1.5 |
| Previous DVT or PE | +1.5 |
| Haemoptysis | +1 |
| Malignancy (on treatment, treated in the last 6 months, or palliative) | +1 |
Using the score safely
- The score is a pre-test probability. The studies paired it with D-dimer and imaging; a low or unlikely score alone does not exclude a clot.
- D-dimer assays differ in sensitivity; the 2000 PE results used the SimpliRED assay. Use your laboratory’s assay and pathway.
- “Alternative diagnosis less likely than PE” is a clinical judgement worth 3 points and drives much of the PE score; record your reasoning.
- National pathways, such as NICE guideline NG158 in the UK, use the two-level DVT and PE Wells scores to choose between D-dimer and imaging. The rules were not validated in pregnancy or in children.
Wells Score Calculator (DVT and PE) FAQ
How do you calculate the Wells score for DVT?
Add 1 point for each of nine findings (active cancer, paralysis or plaster, bedridden or recent surgery, deep-vein tenderness, whole-leg swelling, calf swelling of 3 cm or more, pitting oedema, collateral veins, previous DVT) and subtract 2 if another diagnosis is at least as likely. The Wells score calculator above does this and applies the cut-offs.
What Wells score means PE is likely?
More than 4 points on the two-level PE rule. On the three-level rule, over 6 is high, 2 to 6 moderate and under 2 low.
What is the difference between the two-level and three-level Wells scores?
They use the same criteria with different cut-offs. Two-level (likely/unlikely) is designed to pair with D-dimer testing; three-level (low/moderate/high) was used in the original management studies.
Why is the PE score in halves?
Three PE items — heart rate over 100, recent immobilisation or surgery, and previous DVT/PE — score 1.5 points each.
Can a low Wells score rule out a DVT or PE?
Not by itself. In the original studies a low or unlikely score was combined with a negative D-dimer or imaging before a clot was excluded.
What happens after a confirmed clot?
Treatment follows your guideline and prescriber. For teaching the arithmetic of weight-based infusions, see the heparin drip calculator, which uses only the protocol values you enter.