Wells score calculator for DVT
Pre-test probability of deep vein thrombosis by the Wells criteria.
Subtracts 2 points.
This tool runs entirely in your browser. Nothing you enter is sent to VitalFax or stored anywhere.
- Wells score (DVT)
0
Low pre-test probability — around 5% prevalence.
- Criteria met
- None
This is a reference implementation of a published formula, provided for use by qualified healthcare professionals. It does not diagnose, does not account for the individual circumstances of any patient, and is not a recommendation for treatment. Confirm every result against your own institutional guidance before acting on it. Clinical judgement always takes precedence over a calculator.
About this calculation
The Wells score for DVT estimates pre-test probability so that D-dimer and ultrasound can be interpreted correctly. It is a pre-test tool: it is applied before investigation, not to explain a result already in hand.
Formula
One point per criterion, minus 2 if an alternative diagnosis is at least as likely
- Source
- Wells PS et al., The Lancet (1997)
- Methodology version
- 1.0.0
- Last reviewed
- 2026-10-28
What this does not account for
- This is a pre-test probability tool. Applying it after a D-dimer result is known defeats its purpose.
- Not validated in pregnancy, where a pregnancy-specific pathway should be used.
- The “alternative diagnosis at least as likely” criterion is a clinical judgement and is the main source of variation between assessors.
- A low score with a negative high-sensitivity D-dimer is what excludes DVT. The score alone excludes nothing.