Rex says
Same equations the textbooks use — just way less awkward. Pop in your stats and I'll tell you what the number actually means for you.
Try a scenario
Click to load — tweak from there.Inputs
Result
Wells DVT score
2
Pretest probability
DVT likely
Suggested next step
Proceed to compression ultrasound
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How to use this
- 1Enter active cancer (treated within 6 months or palliative).
- 2Enter paralysis, paresis, or recent leg immobilization.
- 3Enter bedrest ≥3 days or major surgery within 12 weeks.
- 4Enter localized tenderness along deep venous system.
- 5Enter entire leg swollen.
- 6Enter calf swelling >3cm vs other leg.
- 7Enter alternative diagnosis at least as likely as dvt.
- 8Read your wells dvt score on the right — it updates as you type.
- 9Hit Share to keep the scenario or send it to someone.
About this calculator
The Wells score for deep vein thrombosis converts a bedside exam into a pretest probability that determines whether a patient needs D-dimer testing, ultrasound, or both. Each clinical feature (active cancer, paralysis or recent immobilization, recent bedrest or major surgery, localized tenderness along the deep veins, entire leg swelling, calf swelling more than 3cm versus the other leg, pitting edema confined to the symptomatic leg, collateral superficial veins, previous DVT) adds a point, while an alternative diagnosis at least as likely as DVT subtracts two points. A score of 2 or higher suggests DVT is likely and generally warrants ultrasound; a score below 2 suggests DVT is unlikely, and a negative D-dimer in that group can safely rule out DVT without imaging in most validated protocols. This score was derived and validated in outpatients with suspected first DVT; it performs differently in recurrent DVT, pregnancy, or inpatients, where separate rules or lower thresholds for imaging are typically used. This tool is for education and workflow support only — not medical advice. Always verify results with a clinician and use clinical judgment alongside your institution's protocols.
Worked example
Using the values the calculator loads with:
Inputs
- Active cancer (treated within 6 months or palliative): No
- Paralysis, paresis, or recent leg immobilization: No
- Bedrest ≥3 days or major surgery within 12 weeks: No
- Localized tenderness along deep venous system: Yes (+1)
- Entire leg swollen: No
- Calf swelling >3cm vs other leg: Yes (+1)
- Alternative diagnosis at least as likely as DVT: No
Results
- Wells DVT score: 2
- Pretest probability: DVT likely
- Suggested next step: Proceed to compression ultrasound
What each field means
Inputs
- Active cancer (treated within 6 months or palliative)
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
- Paralysis, paresis, or recent leg immobilization
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
- Bedrest ≥3 days or major surgery within 12 weeks
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
- Localized tenderness along deep venous system
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
- Entire leg swollen
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
- Calf swelling >3cm vs other leg
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (+1), No.
- Alternative diagnosis at least as likely as DVT
- Pick the option that matches your situation — the maths changes per option. Choices: Yes (−2), No.
Results
- Wells DVT score
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Pretest probability
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Suggested next step
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What should happen after a low-probability score?
In patients scoring below 2, a negative high-sensitivity D-dimer effectively rules out DVT without imaging in most validated care pathways. A positive D-dimer in this group still needs ultrasound, since D-dimer is sensitive but not specific — many things besides DVT raise it.
Does this score work for a second, recurrent DVT?
Not reliably. The original Wells score was validated for a first suspected DVT. For recurrent DVT, modified criteria exist that account for the difficulty of distinguishing new clot from residual old clot on ultrasound, and clinicians typically rely more heavily on imaging over the score alone.
Can this score be used in pregnancy?
No, pregnancy was excluded from the original validation studies, D-dimer is physiologically elevated throughout pregnancy regardless of clot, and separate pregnancy-adapted diagnostic algorithms (like the LEFT criteria) are used instead.
What if the score is exactly 1 or 2 — is there a 'moderate' category?
The original two-tier model (used here) splits at 2: below 2 is unlikely, 2 or above is likely. Some earlier three-tier versions used low/moderate/high categories, but most modern guidelines have moved to the simpler two-tier system because it performs equally well and is easier to apply consistently.
Accuracy and limitations
- Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.
- Results do not account for medical conditions, medication, or pregnancy.
- Use this as a directional reference, not a diagnosis — talk to a clinician before acting on it.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Wells Score for DVT Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/wells-dvt-score
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/wells-dvt-score" target="_blank" rel="noopener">Wells Score for DVT Calculator — RevenueLab</a> (2026).</p>
Source: [Wells Score for DVT Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/wells-dvt-score) (2026).