6-Minute Walk Test Calculator

What the six minute walk test measures

The six minute walk test (6MWT) measures how far you can walk on a flat, hard surface in six minutes at your own pace. The American Thoracic Society published the standard protocol in its guidelines for the six-minute walk test (ATS, 2002), and it remains the most common supervised walk test in lung and heart clinics. Because you choose your own speed, the test loads many systems at once: lungs, heart, blood, muscles and joints, and the result tracks how much daily activity you can manage.

Clinics use the distance, called the 6MWD, in three ways. It describes current functional capacity, it compares before and after a treatment such as pulmonary rehabilitation, and it carries prognostic weight in conditions like COPD, heart failure and pulmonary arterial hypertension. Alongside distance, the lab records oxygen saturation, heart rate and how breathless or tired you feel, which turn one number into a fuller picture.

This page interprets a distance you already have. It is an estimate and not a diagnosis; your care team reads the test together with your history, medications and other results.

How the test is run, step by step

The ATS 2002 protocol keeps the conditions constant so that two tests can be compared. The course is a straight indoor hallway at least 30 m long with turnaround cones, usually marked every 3 m so the last partial lap can be read off the floor. You rest seated for 10 minutes, then the technician records your baseline breathlessness and leg fatigue on a Borg scale, along with heart rate and oxygen saturation.

At the start you are told to walk as far as possible in six minutes, turning at the cones, and that you may slow down, rest or stop. The technician stands at the start line, does not walk with you, and repeats the same short phrases of encouragement at each minute mark, because extra or absent encouragement changes the distance. Every minute you are told the time remaining. At six minutes you stop where you are and the distance is read from the lap count plus the floor markers.

The same conditions matter as much as the course: same technician, same hallway, similar time of day, same walking aid, and no strenuous exercise in the two hours before. Many labs repeat the test once, because the first walk usually comes out shorter while you learn the pacing.

What a healthy distance looks like

The NIH bookshelf review of the six-minute walk test (updated 2025) puts a typical healthy adult between 400 and 700 m, with median reference values near 494 m for women and 576 m for men in the large reference studies. Distance falls with age and rises with height, and men on average walk farther than women of the same age, which is why the reference equations are sex specific.

The most widely used equations come from Enright and Sherrill (American Thoracic Society journal, 1998), who tested 290 healthy adults aged 40 to 80. For men, 6MWD = 7.57 x height cm - 5.02 x age - 1.76 x weight kg - 309, and the lower limit of normal sits 153 m below the predicted value. For women, 6MWD = 2.11 x height cm - 2.29 x weight kg - 5.78 x age + 667, with a lower limit 139 m below predicted.

The table shows what the equations predict for three sample bodies of each sex. Your own predicted value depends on your measurements, and the calculator above computes it for you.

Read the table as a reminder that a single cutoff, like 350 m, cannot fit every body. An 80 year old woman who walks 405 m has matched the predicted value for her measurements, while the same distance from a 40 year old man would sit far below his.

The equations come from Enright and Sherrill (American Thoracic Society journal, 1998), tested on 290 healthy adults aged 40 to 80. Percent predicted is the walk distance divided by the predicted distance, multiplied by 100.

Reading your result: percent predicted and the bands

Percent predicted is walked distance divided by predicted distance, times 100. Take a 55 year old man who is 170 cm and 70 kg: the equation predicts 7.57 x 170 - 5.02 x 55 - 1.76 x 70 - 309 = 578.6 m, about 579 m. If he walks 480 m, his percent predicted is 480 / 578.6 x 100 = 83 percent.

The lower limit of normal gives a better cutoff than any fixed meter number, because it scales with the body. For that man it is 578.6 - 153 = 425.6 m, so his 480 m sits inside the normal range even though it is below the predicted value. A 420 m walk from the same man would fall below the lower limit and deserve a conversation with his clinician. The bands the calculator reports are:

• at or above predicted, 100 percent or more
• below predicted but within the normal range
• below the lower limit of normal

An absolute number still carries information. The NIH review notes that under 300 m is associated with poorer outcomes in COPD, heart failure and pulmonary hypertension, so a distance that low gets attention no matter what the percent predicted says.

The 30 meter threshold for a real change

Comparing two of your own tests is more useful than comparing with anyone else, and the ATS/ERS technical standard on field walking tests set the change that counts: 30 m or more between tests is clinically important (American Thoracic Society and European Respiratory Society, 2014). A review of patients with different heart and lung conditions found the threshold ranged from 14.0 to 30.5 m, so smaller changes can matter in some populations, but 30 m is the accepted planning number.

Worked example: a patient walks 410 m before pulmonary rehabilitation and 445 m after. The gain is 35 m, past the threshold, which supports the program having worked. A second patient moves from 410 m to 422 m, a gain of 12 m, which sits within the noise of pacing and encouragement and should not be called improvement.

For the threshold to mean anything, both walks need the same setup: same course, same technician, same encouragement script, same shoes and walking aid, similar time of day. If the second test ran on a longer straight corridor or followed a practice walk that the first did not, part of the change belongs to the conditions, not to you.

The Borg scale: rating breathlessness and leg fatigue

Before and after the walk you rate two sensations on a Borg scale: breathlessness and leg fatigue. Labs use either the 0 to 10 ratio scale or the classic 6 to 20 rating of perceived exertion. On the 0 to 10 scale, 0 means nothing at all, 3 is moderate, 5 is severe, 7 approaches the maximum and 10 is the hardest you can imagine. On the 6 to 20 scale, 6 is no exertion at all, 9 is very light effort, 13 is somewhat hard, 15 is hard, 17 is very hard and 20 is maximal.

The numbers are recorded at rest and within a minute of finishing, and the change matters as much as the end value. A walker who starts at 1 and finishes at 5 worked much harder than a walker who finished at 2, even when the distances match. In some clinics a large rise in breathlessness together with a drop in oxygen saturation says more than the distance alone, because it shows the limit was reached rather than the pace chosen.

The worksheet asks for a rating from 6 to 20. These are the anchor points most clinics use, and the technician reads them out before the walk and again at the end.

Most people land between 11 and 15 at the end of a good six-minute walk. The rating is a companion to the distance, not a substitute for it, so a clinician reads the two together.

Things that move the number without any change in health

The 6MWD responds to the setup as well as the body. Encouragement scripts, corridor length, the number of turns, practice walks, time of day, footwear, a walking aid and supplemental oxygen can each shift the distance by tens of meters. The reference equations also predict shorter distances for older, shorter and heavier walkers, so a result that looks low next to a fit 30 year old can sit inside the normal range for an 80 year old.

• A first test is usually shorter than a second, purely from learning the pacing
• A long straight course produces longer distances than the same floor area with frequent turns
• Someone who walks alongside you, even in silence, tends to push the distance above what the protocol allows

That is why labs standardize everything, and why the comparison that counts is your second test against your first under the same conditions, tracked through the 30 m threshold in the section above.

Safety, stopping rules and what this page does not do

The walk test is done where emergency help is close at hand, with staff trained in resuscitation, per the ATS 2002 guidelines. The test stops early for chest pain, breathlessness you cannot tolerate, leg cramps, a staggering gait, sudden sweating or looking pale. Conditions such as unstable angina, a recent heart attack or an uncontrolled heart rhythm are reasons a clinician may cancel the test, and that decision belongs to the care team that knows your history.

This page is an estimator. It does not diagnose, it does not clear anyone for exercise, and a below average distance has many explanations besides disease, including deconditioning, joint pain, low motivation on the day or a course with too many turns. Bring the printed numbers to the clinician who ordered the test, and let them read the distance alongside your oxygen levels, medications and goals.