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VO2 Max Calculator
Estimate VO₂ max (ml/kg/min) from a field test — the Cooper 12-minute run ((distance_m − 504.9) / 44.73), the Rockport 1-mile walk (time + ending HR + weight), or the Uth resting-HR ratio (15 × max HR / resting HR) — then read it against age/sex Cooper/ACSM fitness norms. When the Uth max HR is unmeasured we substitute Tanaka (208 − 0.7 × age) and flag the chained estimate. A field estimate, not a lab VO₂ max; general fitness guidance. Accurate, instant and free — for United States.
What these mean:
What these mean:
What these mean:
By the Cooper 12-minute run method, your estimated VO₂ max is ≈ 51.3 ml/kg/min. Fitness category: Superior. A field-test estimate, not a lab VO₂ max — general fitness guidance.
VO₂ max
51.3 ml/kg/min
Fitness category: Superior
A field-test estimate — not a lab VO₂ max
How Garmin & Apple Watch estimate VO₂ max
An estimate — general fitness guidance
How we calculate this
Reviewed by Reckonist Editorial · Last reviewed July 2026. Figures follow the methods and sources set out in our editorial standards.
VO₂ max from the Cooper, Rockport or Uth heart-rate-ratio field tests. A field estimate, not a lab VO₂ max — general fitness guidance.
Cooper · Uth 2004 · ACSM norms
Take it further: set your training pace with the Running Pace Calculator, and dial in your effort with the Heart Rate Zone Calculator.
Three field tests for VO₂ max — Cooper, Rockport & resting-HR
VO₂ max — your body’s maximum rate of oxygen use, in ml/kg/min — is estimated three ways: the Cooper 12-minute run, the Rockport 1-mile walk, and the Uth resting-heart-rate ratio. Each is a field estimate, not a lab measurement, and every value carries its unit (ml/kg/min).
Cooper 12-minute run
distance in 12 min
VO₂ max = (distance_m − 504.9) / 44.73
Run as far as you can in 12 minutes; more distance means a higher VO₂ max.
Rockport 1-mile walk
time + ending HR + weight
132.853 − 0.0769·wt − 0.3877·age + 6.315·sex − 3.2649·min − 0.1565·HR
Walk one mile fast; a faster time and lower ending HR raise the estimate.
- 1Subtract the constant: 2800 − 504.9 = 2295.1.
- 2Divide by 44.73: 2295.1 ÷ 44.73 = ≈ 51.3 ml/kg/min.
- 3Interpret vs norms: For a man in his 30s, ≈ 51.3 lands in the top band — Superior.
Worked example · Uth resting-HR, HRmax 190 / HRrest 50
Age & sex fitness norms
A VO₂ max number only means something against your age and sex. This tool classifies your result into Cooper/ACSM fitness bands — Poor, Fair, Good, Excellent, Superior — which decline with age and sit a few points lower for women. Some illustrative male thresholds (ml/kg/min):
| Age (M) | Good | Excellent | Superior |
|---|---|---|---|
| 20–29 | 43–47 | 48–52 | > 52 |
| 30–39 | 42–46 | 47–51 | > 51 |
| 40–49 | 40–44 | 45–48 | > 48 |
| 50–59 | 36–40 | 41–44 | > 44 |
Women’s bands run roughly 5–6 ml/kg/min lower at each age. The tool applies the correct table for your age and sex automatically.
How Garmin & Apple Watch estimate VO₂ max
Wearables don’t run a field test. Garmin and Apple Watch estimate VO₂ max from the relationship between your heart rate and your pace (or power) during ordinary runs — a sub-maximal regression the device refines over many activities. That is why the reading can drift when your HR strap or GPS pace is noisy.
Why your watch and this tool can disagree
A field estimate — not a lab VO₂ max
A true VO₂ max comes from a graded maximal test with gas analysis in a lab. Cooper, Rockport and Uth approximate that value from things you can measure yourself, so expect a few points of error.
The chained-HRmax assumption
Frequently asked questions
This tool offers three field tests. The Cooper 12-minute run uses the distance you cover: VO₂ max = (distance_m − 504.9) / 44.73. The Rockport 1-mile walk uses a regression on your walk time, ending heart rate, weight, age and sex. The Uth resting-HR method uses the ratio VO₂ max ≈ 15 × (max HR / resting HR). All are field estimates in ml/kg/min, not a lab measurement.
It depends on age and sex. Using Cooper/ACSM fitness norms, a man in his 20s is roughly Good at 47–52 and Excellent above 52 ml/kg/min, while a man in his 50s reaches Good at 40–44 and Excellent above 44. Women's bands sit a few points lower at every age. VO₂ max declines with age, so this tool applies the correct age/sex band automatically and labels your category from Poor to Superior.
Differently from a field test. Wearables estimate VO₂ max from the relationship between your heart rate and your pace (or power) during ordinary runs — a sub-maximal regression the device refines over many activities. It is not a maximal effort or a lab test, so the number is a modelled estimate that can drift if your HR data or GPS pace is noisy.
The Uth (heart-rate-ratio) method — VO₂ max ≈ 15 × (max HR / resting HR) — is convenient because it needs no exercise test, but it silently depends on knowing your max HR. If you have not measured your max HR, this tool substitutes the Tanaka estimate (208 − 0.7 × age), which means the result is an estimate resting on another estimate. Measuring your true max HR, or using a run-based test, gives a better figure.
No. A true VO₂ max comes from a graded maximal exercise test with gas analysis in a lab. Field formulas like Cooper, Rockport and Uth approximate that value from things you can measure yourself — distance, walk time and heart rate — so expect a few points of error. Treat the result as general fitness guidance and a good ballpark, not a clinical measurement.
If you can run hard for 12 minutes, the Cooper test is simple and well validated. If you prefer walking or are less fit, the Rockport 1-mile walk is gentler and uses your ending heart rate. If you want no exercise test at all, the Uth resting-HR method needs only your resting and maximum heart rate — but it is the roughest, especially when the max HR is estimated rather than measured.
Methods, formulas & references
Methodology: Cooper 12-min run — VO₂ max = (distance_m − 504.9) / 44.73; Rockport 1-mile walk — 132.853 − 0.0769·wt(lb) − 0.3877·age + 6.315·sex(1 M/0 F) − 3.2649·time(min) − 0.1565·endHR; Uth resting-HR — VO₂ max ≈ 15 × (max HR / resting HR), max HR from Tanaka (208 − 0.7 × age) when unmeasured. Norms are age/sex Cooper/ACSM bands. All calculations run client-side and nothing is stored. A field estimate, not a lab VO₂ max — general fitness guidance, not medical advice.
Cross-links
How we calculate this
Reviewed by Reckonist Editorial · Last reviewed July 2026. Figures follow the methods and sources set out in our editorial standards.
VO₂ max from the Cooper 12-min run, Rockport 1-mile walk or Uth resting-HR ratio field tests, interpreted against age/sex fitness norms. A field estimate, not a lab VO₂ max — general fitness guidance, not medical advice.
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