6-Minute Walk Test Calculator (predicted distance and % predicted, Enright 1998)

Understanding the 6-minute walk test calculator — concept and principle

This calculator compares a six-minute walk distance with the value predicted for a healthy adult of the same sex, age, height and weight, using the Enright and Sherrill (1998) reference equations. It shows the predicted distance, the result as a percentage of predicted, the difference in metres and whether the age lies within the study range. Physiotherapists, pulmonary and cardiac rehabilitation staff and patients tracking progress use it.

Walked vs predicted — with the default inputs: 85% of predicted.

How it is calculated

Men: predicted 6MWD (m) = 7.57 × height (cm) − 5.02 × age − 1.76 × weight (kg) − 309
Women: predicted 6MWD (m) = 2.11 × height (cm) − 2.29 × weight (kg) − 5.78 × age + 667
% predicted = distance walked ÷ predicted × 100
Difference = distance walked − predicted

The equations were derived from healthy adults aged 40–80.

The principle

In the six-minute walk test a person walks as far as possible in 6 minutes back and forth along a flat corridor, usually 30 m long, with standard encouragement and rests allowed. The distance reflects the combined function of the heart, lungs, muscles and circulation during everyday-level exercise. Enright and Sherrill tested 117 healthy men and 173 healthy women and found that height, age and weight explained about 40% of the differences between people. Taller people take longer strides; older and heavier people tend to walk shorter distances.

Worked example

Defaults: male, 62 years, 170 cm, 78 kg, 450 m walked.

Predicted = 7.57 × 170 − 5.02 × 62 − 1.76 × 78 − 309 = 1,286.9 − 311.24 − 137.28 − 309 = 529 m.
% predicted = 450 ÷ 529.38 × 100 = 85%.
Difference = 450 − 529 = -79 m.
Age 62 is within the study range: Yes.

How to read the result

Because the equations explain only part of the variation between healthy people, a single percentage should be read together with the person's history and symptoms. Changes in the same person over time, measured the same way, are often more informative than one comparison with the prediction. Shorter courses with more turns give lower distances, so use the standard corridor length.

Common mistakes

Using a short course or a treadmill, which changes the distance.
Applying the equations to people far outside ages 40–80.
Comparing tests done with and without supplemental oxygen or walking aids.
Not allowing a practice test, which can improve the second result.

Keep in mind: Not a diagnosis. The test should be done with trained staff following the standard protocol, and stopped if chest pain, severe breathlessness or dizziness occurs.

Frequently asked questions

What is a normal six-minute walk distance?

It depends on age, sex, height and weight; this equation gives about 529 m for the default man.

Why does % predicted matter?

It puts the distance in context for a person's size and age.

Is a change of a few metres meaningful?

Small changes can fall within test-to-test variation; clinicians look at larger, consistent changes.

Sources: Enright PL, Sherrill DL, "Reference equations for the six-minute walk in healthy adults", Am J Respir Crit Care Med 1998;158(5 Pt 1):1384–1387

Checked 9 Nov 2026. Enright PL, Sherrill DL, “Reference equations for the six-minute walk in healthy adults”, Am J Respir Crit Care Med 1998;158(5 Pt 1):1384–1387 (abstract: equations, sample and variance explained).

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