Wells Score for DVT Calculator
Estimate pre-test probability of deep vein thrombosis using the Wells clinical prediction rule.
Understanding this tool
Why nurses use it
The Wells score estimates pre-test probability of deep vein thrombosis (DVT) from bedside findings — helping decide whether urgent imaging (ultrasound) or D-dimer testing is warranted.
When to use it
Use for leg swelling, pain, or DVT suspicion in emergency or ward settings — follow NICE 2-level Wells pathway (≥2 likely, ≤1 unlikely).
Calculate
How to use this calculator
- Work through Wells criteria honestly — including alternative diagnosis if likely.
- Sum the score and apply your local DVT pathway (ultrasound and/or D-dimer by 2-level Wells result).
How the calculation works
Weighted points for clinical features (cancer, immobility, tenderness, swelling, etc.). NICE uses 2-level interpretation: ≥2 = DVT likely; ≤1 = DVT unlikely.
Formula used by this tool — verify units before applying at the bedside.
Worked example
Limitations & clinical notes
- Imaging decisions remain prescriber-led.
- This tool uses the NICE 2-level Wells interpretation (≥2 likely, ≤1 unlikely).
References
Key sources: NICE NG158 — Venous thromboembolic diseases; Wells PS — DVT clinical prediction rule.
Don’t miss new nursing tools
Subscribe for alerts when we add calculators, clinical scores, and reference updates to NurseOnShift.
Disclaimer: This calculator is for educational and bedside double-check purposes only. It does not replace institutional protocols, prescriber orders, pharmacist verification, or clinical judgment. Always follow your local policies — especially for high-risk medications, infusions, pediatrics, and critical care. If the patient is acutely unwell, escalate immediately rather than relying on any calculator output.