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VO₂ max estimate by age

Choose a method and enter your heart-rate or completed walk data to estimate VO₂ max. Age alone cannot measure fitness.

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Enter your measurements above, or try the worked example. Entry limits are not healthy reference ranges.

Inputs and results stay in this page's memory. They are not saved, uploaded or added to links. Changing units clears that value.

Illustration of a running shoe, sport watch, lungs and oxygen symbols representing aerobic fitness.

What this result means

VO₂ max describes maximum oxygen use during exercise, commonly relative to body weight. Age helps some estimation equations, but it cannot measure an individual's fitness on its own. Choose a method suited to your data and compare estimates only within a consistent method. [1][2][3]

Choose a method that fits your data

Age plus resting heart rate is the shortest form, but the original heart-rate-ratio study involved 46 trained men aged 21–51. If that does not fit you, do not treat its number as a validated personal estimate. The completed one-mile walk method has different inputs and supports female and male coefficients. [1][3]

Using wearable data

A wearable's resting heart rate can supply a resting input when that method is suitable. Its own VO₂ max estimate is a different algorithm and may use pace, GPS, movement and other signals. Keep the device and activity context consistent when following a trend; this page does not connect to or upload wearable records.

Use existing measurements safely

Enter data from a test you have already completed appropriately. Do not perform a maximum-effort test to obtain a missing heart rate. Chest pain, faintness, unusual breathlessness or a relevant condition needs suitable assessment before exercise testing. This calculator is not exercise clearance.

Can VO₂ max be calculated from age alone?

No. Two people the same age can have very different fitness. Age can help estimate maximum heart rate or contribute to a multi-input equation; it cannot replace a fitness measurement. That is why every mode here requires heart-rate or walk data. [1][2]

What is a good VO₂ max for my age?

Reference values depend on the population, sex categories, test protocol and whether the result was measured or estimated. This page does not invent an age percentile from a heart-rate estimate. If you need a meaningful comparison, use an appropriate reference set with the same measurement method.

How close is this to a laboratory VO₂ max test?

Neither method measures oxygen use directly. In the original heart-rate study, error was larger when maximum heart rate was predicted rather than measured, and validation was limited to trained men. A laboratory test can answer a different and more direct question. [1]

What counts as a one-mile walk result?

Use an appropriately completed Rockport track-walk protocol, with walk time, finishing heart rate, age, weight and the equation's sex coefficient. The original study used at least two fast one-mile walks with the two fastest times within 30 seconds. A casual stroll, jog, treadmill walk or different distance is not interchangeable. 15 minutes 30 seconds is 15.5 minutes. These are criteria for existing test data, not instructions to perform a test. [3][4]

Why is it different from my Apple Watch or Garmin?

Different methods use different signals, assumptions and sampling conditions. A resting-heart-rate ratio is not a reproduction of either wearable's algorithm. Treat discrepancies as a reason to check the method and inputs, not proof that one device is broken.

Can I use this number to choose training intensity?

No. This educational estimate does not prescribe heart-rate zones or exercise intensity. Training choices should consider your health, experience and relevant professional advice. Track comparable activity and measurements rather than chasing a single calculator number.

Formula and assumptions

Formula
Heart-rate estimate = 15.3 × HRmax / HRrest; age-predicted HRmax = 208 − 0.7×age. Rockport = 132.853 − 0.0769×weight(lb) − 0.3877×age + 6.315 if male − 3.2649×time(min) − 0.1565×finishing HR. [1][2][3][4]
Version
Uth heart-rate ratio; Tanaka predicted HRmax; Rockport walk, uth-2004.tanaka-2001.rockport-kline-1987.v1
Rounding
Keep intermediate values unrounded. Display the VO₂ estimate to one decimal and the heart rate used to whole bpm.
Worked example
For a trained man aged 40 with resting heart rate 60 bpm, the age-predicted maximum is 208 − 0.7×40 = 180 bpm. The ratio estimate is 15.3×180/60 = 45.9 mL/kg/min. It is an example of this limited estimation method, not a laboratory measurement or fitness target. [1][2]

Who this is for — and when not to use it

Intended use

Educational estimation from existing suitable fitness data. The resting-heart-rate methods are limited here to trained men aged 21–51; the Rockport methods to adults aged 30–69.

Not intended for

Exercise clearance, maximal-test instructions, medication decisions, diagnosis, a universal age/sex percentile or a substitute for cardiopulmonary exercise testing.

Exclusions

  • Heart-rate-altering medication or rhythm conditions for the heart-rate methods.
  • Applying the narrow heart-rate validation to women, older adults or other unvalidated groups.
  • Symptoms or a condition that makes exercise unsafe; pregnancy or acute illness without appropriate professional guidance.
  • Using a casual stroll, a different distance or a resting pulse as a Rockport test input.

Evidence sources

  1. 1. Estimation of VO2max from the ratio between maximum and resting heart rate — Uth et al., European Journal of Applied Physiology. Accessed Oct 4, 2026.
  2. 2. Age-predicted maximal heart rate revisited — Tanaka et al., Journal of the American College of Cardiology. Accessed Oct 4, 2026.
  3. 3. Estimation of VO2max from a one-mile track walk, gender, age and body weight — Kline et al., Medicine and Science in Sports and Exercise. Accessed Oct 4, 2026.
  4. 4. Methods for estimating cardiorespiratory fitness: Rockport equation — University of Houston Exercise Science. Accessed Oct 4, 2026.