6-Minute Walk Test Calculator — % Predicted (6MWT)

Formula

How this is calculated

The six-minute walk test (6MWT) measures functional exercise capacity by recording the maximum distance a person can walk in six minutes on a flat, hard surface. It is widely used in clinical cardiology and pulmonology to assess patients with heart failure, COPD, pulmonary hypertension and other conditions, and to track response to treatment.

Because walk distance naturally depends on a person's age, sex, height and body weight, a raw distance is only meaningful when compared to a predicted normal value derived from healthy peers. This calculator uses the reference equations published by Enright and Sherrill (Am J Respir Crit Care Med, 1998) — one of the most cited sets of equations in the field. The percentage of predicted (% pred) is then simply: actual distance ÷ predicted distance × 100. Values below the lower limit of normal (LLN, approximately the 5th percentile of healthy adults) may indicate reduced functional capacity worth discussing with a clinician.

Important limitations: the equations were validated on adults aged 40–80, so results outside that range are extrapolations. The test requires a standardised protocol: a 30-metre straight corridor, rest before the test, standard encouragement phrases, and oxygen-saturation monitoring in clinical settings. This calculator provides a reference calculation for educational and screening purposes only — clinical decisions should be made with full patient context by a qualified healthcare professional.