Wells Score for DVT Calculator

The Wells score for deep vein thrombosis (DVT) is a clinical prediction rule that estimates the pretest probability that a patient with leg symptoms has a DVT. You add one point for each of nine findings (such as active cancer, leg swelling, localized tenderness, or a previously documented DVT) and subtract two points if an alternative diagnosis is at least as likely. The total places the patient in a likely or unlikely group before any imaging or blood test.

In the two-level model used by NICE and most emergency departments, a total of 2 or more means DVT is likely, and 1 or less means DVT is unlikely. When DVT is unlikely, a negative high-sensitivity D-dimer can rule it out without imaging. When DVT is likely, a proximal leg vein ultrasound is the usual next step.

Each of these adds one point: active cancer, paralysis or recent cast immobilization of the leg, being bedridden 3 or more days or major surgery within 12 weeks, localized tenderness along the deep veins, an entire swollen leg, calf swelling at least 3 cm larger than the other leg, pitting edema confined to the symptomatic leg, collateral superficial veins, and a previously documented DVT. The tenth item, an alternative diagnosis at least as likely as DVT, subtracts two points.

They share the name and the author but use different criteria and cutoffs. The DVT score focuses on signs in the leg and ranges from -2 to 9, while the pulmonary embolism (PE) score weighs items like hemoptysis and heart rate over 100 and ranges from 0 to 12.5. Use the DVT version for suspected leg clots and the PE version for suspected lung clots.

No. A score in the unlikely group lowers the probability but does not exclude DVT by itself. The standard pathway pairs an unlikely score with a high-sensitivity D-dimer, and only a negative D-dimer plus an unlikely score reliably rules out DVT without ultrasound.

No. This calculator is for education only and is not a substitute for professional medical advice, diagnosis, or treatment. The Wells score is one input among many, and decisions about D-dimer testing, ultrasound, and anticoagulation should be made by a qualified clinician using the full clinical picture.