Calc Function

    • Calcs that help predict probability of a diseaseDiagnosis
    • Subcategory of 'Diagnosis' designed to be very sensitiveRule Out
    • Disease is diagnosed: prognosticate to guide treatmentPrognosis
    • Numerical inputs and outputsFormula
    • Med treatment and moreTreatment
    • Suggested protocolsAlgorithm





    Chief Complaint


    Organ System


    Patent Pending

    6 Minute Walk Distance

    Calculates reference values for distance walked, as a measure of functional status.


    Do not use if unstable angina or MI less than 1 month prior. Relative contraindications: resting HR over 120, systolic BP over 180, or diastolic BP over 100. Stop if any of the following occur: chest pain, intolerable dyspnea, leg cramps, staggering, diaphoresis, or pale appearance.

    Why Use
    • Original cohort did not include patients <40 or >80 years old and non-Caucasian patients.
    • Widely used across specialities dealing with geriatrics and/or chronic disease.
    • Intended to be carried out along a flat straight walking course 30 m (100 ft) long, with brightly colored tape marking the starting line (as well as every 60 m lap). Use of a treadmill is not recommended. More detailed instructions are available in the American Thoracic Society guidelines.
    • Known to be less accurate in shorter patients, who have shorter strides.
    • Primarily used to assess response to interventions in patients with moderate to severe heart or lung disease (American Thoracic Society guidelines).
    • Can be used to measure functional status in patients who are elderly, frail, and/or otherwise unable to tolerate treadmill exercise tests.
    • Commonly used in patients with COPD, heart failure, arthritis, and neuromuscular disorders.


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    Next Steps
    Creator Insights


    Treat the underlying disorder. 6MWD can be serially measured to assess progression of disease and response to treatment.


    Male patients:

    6MWD in meters = (7.57 × height in cm) – (5.02 × age) – (1.76 × weight in kg) – 309

    Lower limit of normal = 6MWD - 153

    Female patients:

    6MWD in meters = (2.11 × height in cm) – (2.29 × weight in kg)  – (5.78 × age) + 667

    Lower limit of normal = 6MWD - 139

    Dr. Paul L. Enright

    About the Creator

    Paul L. Enright, MD, is a retired research professor of medicine from the University of Arizona in Tucson. He reviews manuscripts for several pulmonary journals. Dr. Enright’s interests include pulmonary function testing, occupational lung disease, and diagnostic techniques for asthma and COPD.

    To view Dr. Paul L. Enright's publications, visit PubMed

    About the Creator
    Dr. Paul L. Enright
    Teaching Resources