Rockport one-mile walk VO2 max calculator
This Rockport walk test VO2 max calculator estimates maximal oxygen uptake in millilitres per kilogram per minute from a timed one-mile walk, the heart rate measured at the finish, body weight, age, and sex.
Run — free
The Rockport Fitness Walking Test is a classic submaximal field protocol used in fitness labs, coaching, and workplace wellness when a full graded treadmill test is impractical. The engine applies the published Kline and colleagues regression with fixed coefficients, converts weight between kilograms and pounds when needed, and returns a deterministic estimate plus the normalised inputs. Small reference checks include a middle-aged adult walking the mile in about fifteen minutes with a moderate recovery pulse, which should land in a plausible mid-thirties to forties range of millilitres per kilogram per minute depending on sex and body mass. There is no network call, no random sampling, and no dependence on the current date. Use it free in the browser for personal tracking and classroom demos, or call the API at $0.002 per successful request when you need reproducible fixtures in coaching software, research pipelines, or automated wellness reports.
How to use it
Enter your values in the form above. The tool checks them before calculating and shows the result on the same page.
Check your inputs
Use the labels and units shown next to each field. If something is missing or outside the allowed range, the page points to the field to fix.
Use it again or automate it
Use the browser tool for individual checks and the API when you need the same capability in an automated workflow.
What you can do with it
Get an answer now
Enter one set of values and see the result without building a spreadsheet or script.
Compare scenarios
Change one value at a time and rerun the calculation to understand what affects the result.
Automate repeated work
Use the API when the same calculation needs to run inside your product or workflow.
FAQ
What does the Rockport VO2 max calculator cost?
It is free in your browser on this page. Through the API a successful request costs $0.002; invalid inputs are not charged.
Which formula does this tool use?
The Kline et al. (1987) Rockport Fitness Walking Test regression: VO2max = 132.853 − 0.0769×weight_lb − 0.3877×age + 6.315×sex − 3.2649×time_min − 0.1565×HR, with sex coded 1 for male and 0 for female.
What happens if time, heart rate, weight, or age is zero or negative?
The input is rejected with invalid_input. Non-positive values are not valid for the Rockport estimate.
Can I enter weight in kilograms?
Yes. weight_unit defaults to kg; set it to lb if your scale is in pounds. The equation uses pounds internally and the response echoes both units.
Is this a medical diagnosis of cardiorespiratory fitness?
No. It is a deterministic field-test estimate from published coefficients. It does not replace graded exercise testing or clinical advice.
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/health/vo2max-rockport \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"heart_rate":140,"weight":70,"age":40,"sex":"male","time_min":15.5}'const res = await fetch("https://api.kit.forhosting.com/health/vo2max-rockport", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"heart_rate": 140,
"weight": 70,
"age": 40,
"sex": "male",
"time_min": 15.5
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/health/vo2max-rockport",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"heart_rate": 140,
"weight": 70,
"age": 40,
"sex": "male",
"time_min": 15.5
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/health/vo2max-rockport", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"heart_rate":140,"weight":70,"age":40,"sex":"male","time_min":15.5}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"heart_rate":140,"weight":70,"age":40,"sex":"male","time_min":15.5}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/health/vo2max-rockport", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"heart_rate": 140,
"weight": 70,
"age": 40,
"sex": "male",
"time_min": 15.5
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "health.vo2max_rockport",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
max_age | 120 |
max_weight_lb | 1000 |
max_time_min | 60 |
max_hr | 250 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |