Six Minute Walk Distance Calculator
Predict the six-minute walk distance for a healthy adult and see how a real walk compares with the expected value.
What it does
The six-minute walk test measures how far a person walks on a flat course in six minutes. It is used in pulmonary, cardiac and rehabilitation settings because it reflects everyday exercise capacity without a treadmill or a maximal effort. The test is simple, but the distance still needs a reference point, because a tall young adult and a shorter older adult should not be compared directly.
Enright and Sherrill published reference equations from 117 healthy men and 173 healthy women aged 40 to 80. Their model uses height, weight, age and sex, and it explains about 40% of the variation in distance within that group. The equations remain a common way to put a walk result into context, and the American Thoracic Society statement on the test uses the same standard protocol.
This calculator first predicts the distance for the person you describe, then compares the walk that was actually completed. The percent predicted is the walked distance divided by the predicted distance. A result of 100% means the walk matched the prediction, while 80% means it reached four fifths of it. The band is a reading aid, not a diagnosis.
Protocol affects the number as much as physiology. The ATS statement calls for a 30 m corridor, a chair at each end, the same instructions before the test, and a standard phrase of encouragement each minute. A corridor with more turns, a different pace of encouragement or a test stopped early for symptoms will not be comparable with a repeat done another way.
The equations describe healthy adults. They do not account for heart failure, lung disease, joint pain, medication or motivation, and they were not fitted for children or for adults younger than 40 in the original sample. A low result is a reason to look at the whole test, including symptoms, oxygen saturation and recovery, rather than a label on its own.
How to use
- Choose metric or imperial units.
- Select the sex used by the reference equation. The equation has separate coefficients for men and women.
- Enter age, height and weight. Use the same measurements you would give a clinic, without shoes for height.
- Enter the distance from a six-minute walk on a flat course. For feet and inches, convert the height to total inches first.
- Read the predicted distance, the percent of predicted, and the band.
- If you are tracking progress, repeat the test on the same course, at the same time of day, with the same encouragement.
Formula
- 6MWD
- Predicted six-minute walk distance in meters.
- height (cm)
- Standing height without shoes, in centimeters.
- age (years)
- Age at the time of the test, in whole years.
- weight (kg)
- Body weight at the time of the test, in kilograms.
The two equations share a form but not their coefficients. Men gain more predicted distance per centimeter of height, while women have a larger positive constant. The original sample covered ages 40 to 80, and the authors reported an R squared of about 0.40. A 2020 erratum was issued for the article, and the coefficients here match the original published abstract. Outside the fitted age range, treat the result as a rough context rather than a precise target.
Worked example
Example: a 40 year old man, 175 cm and 70 kg, walks 650 m
Defaults: metric units, male, age 40, height 175 cm, weight 70 kg, distance walked 650 m.
- Multiply height by 7.57: 175 x 7.57 = 1,324.75.
- Multiply age by 5.02: 40 x 5.02 = 200.8.
- Multiply weight by 1.76: 70 x 1.76 = 123.2.
- Subtract the three terms and the constant: 1,324.75 - 200.8 - 123.2 - 309 = 691.75 m.
- Divide the walked distance by the prediction: 650 / 691.75 = 0.9396, so 94.0 %.
- The tool shows 692 m predicted, 94.0 % of predicted, and the band 80 to 99% of predicted.
Reference table
| Profile | Predicted distance | How it is built |
|---|---|---|
| Man, 30 years, 180 cm, 75 kg | 771 m | 7.57 x 180 - 5.02 x 30 - 1.76 x 75 - 309 |
| Man, 40 years, 175 cm, 70 kg | 692 m | 7.57 x 175 - 5.02 x 40 - 1.76 x 70 - 309 |
| Man, 60 years, 170 cm, 80 kg | 536 m | 7.57 x 170 - 5.02 x 60 - 1.76 x 80 - 309 |
| Woman, 40 years, 165 cm, 60 kg | 647 m | 2.11 x 165 - 2.29 x 60 - 5.78 x 40 + 667 |
| Woman, 60 years, 160 cm, 70 kg | 497 m | 2.11 x 160 - 2.29 x 70 - 5.78 x 60 + 667 |
Limits
- Fitted for healthy adults aged 40 to 80 in the original study, so children and younger adults sit outside the reference range.
- Describes a healthy reference, not the expected distance for a person with heart or lung disease.
- One test includes measurement noise from effort, encouragement, corridor layout and symptoms.
- Does not use diagnosis, medication, oxygen use or the reason the test was ordered.
Common mistakes
- Using a corridor shorter than 30 m, which adds turns and lowers the distance.
- Giving different encouragement on repeat tests, which makes two results look more different than they are.
- Entering height in inches while the form is set to centimeters.
- Comparing percent predicted from two different reference equations as if they were the same scale.
- Reading one low result as a diagnosis instead of checking symptoms, oxygen saturation and the test conditions.
Try it yourself
Quick checks. Answers sit tucked under each question.
What distance is predicted for a 60 year old woman who is 160 cm tall and weighs 60 kg?
2.11 x 160 = 337.6, 2.29 x 60 = 137.4, and 5.78 x 60 = 346.8. Then 337.6 - 137.4 - 346.8 + 667 = 520.4, so about 520 m.
A 30 year old man is 180 cm tall, weighs 80 kg and walks 700 m. What is his percent predicted?
7.57 x 180 = 1,362.6, 5.02 x 30 = 150.6 and 1.76 x 80 = 140.8. The prediction is 1,362.6 - 150.6 - 140.8 - 309 = 762.2 m. Then 700 / 762.2 = 91.8 % of predicted.
A walk of 400 m against a predicted distance of 600 m falls in which band?
400 / 600 = 66.7 %, which is below 80% of predicted and sits in the lowest band on this page.
Questions
What is a normal six-minute walk distance?
There is no single cutoff. The expected distance depends on age, height, weight and sex, so the result is usually read as a percent of the predicted value for that person.
Why does the test last six minutes?
Six minutes is long enough to reflect submaximal exercise capacity and short enough to repeat in a clinic without exhausting most patients.
Does this equation work for children?
No. The reference equations came from adults aged 40 to 80, and children need age specific reference values and a different protocol.
Does the course layout change the result?
Yes. A longer straight corridor with fewer turns usually gives a longer distance than a short course with frequent turns, which is why the ATS statement asks for a 30 m course and the same setup on repeat tests.
How much change between tests matters?
Many clinics treat a change of about 30 m as a practical signal, but the meaning depends on the person, the symptoms and the test conditions. A single small change is not proof of a real change in capacity.
Can I use this for fitness tracking?
It can track submaximal endurance, but a maximal test such as a VO2 max test says more about aerobic fitness. The six-minute walk is designed for clinical and functional assessment.
Sources
- Enright and Sherrill: reference equations for the six-minute walk in healthy adults, PubMed
- American Thoracic Society statement: guidelines for the six-minute walk test, PubMed