Wells Score Calculator for DVT

Wells criteria for clinical probability of deep vein thrombosis.

For educational and clinical reference. Not a substitute for medical judgment. See the medical disclaimer.

Active cancer (treatment within 6 mo or palliative)

Paralysis, paresis, or recent plaster immobilization of legs

Bedridden ≥ 3 days or major surgery within 12 weeks

Localized tenderness along the deep venous system

Entire leg swollen

Calf swelling ≥ 3 cm larger than asymptomatic side

Pitting edema confined to symptomatic leg

Collateral superficial veins (non-varicose)

Previously documented DVT

Alternative diagnosis as likely or more likely than DVT

Score

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Interpretation

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References

Wells PS, Anderson DR, Bormanis J, et al. Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet. 1997;350(9094):1795-1798.

What is Wells Score Calculator for DVT?

The Wells score for deep vein thrombosis (DVT) is a clinical decision rule that estimates the pre-test probability of lower-extremity DVT before imaging. Published by Wells et al. in 1997 and modified in 2003, it assigns one point each to nine clinical features — including active cancer, immobilization, recent surgery, calf swelling >3 cm, pitting edema, collateral veins, and tenderness along the deep venous system — and subtracts two points when an alternative diagnosis is equally likely. A score ≥2 indicates DVT likely, while <2 with a negative high-sensitivity D-dimer safely excludes DVT without ultrasound.

How to use

Check each clinical criterion.
The Wells DVT score and probability update instantly.
Pair with D-dimer testing; ultrasound for moderate–high probability.

Frequently asked questions

When to use Wells DVT?

For patients with unilateral leg swelling, pain, or other clinical features suggestive of deep vein thrombosis, to risk-stratify the pre-test probability.

2-tier vs 3-tier?

The 2-tier version uses ≤ 1 (unlikely) and ≥ 2 (likely). The 3-tier (above) gives sharper graded probabilities and pairs well with D-dimer thresholds.

What if Wells is low and D-dimer is negative?

Low Wells + negative high-sensitivity D-dimer effectively rules out DVT and avoids ultrasound.

Can ultrasound replace Wells?

In high-probability patients, a single negative ultrasound may miss isolated calf DVT; repeat ultrasound at 1 week or a negative D-dimer is recommended for definitive exclusion.

Last updated June 28, 2026