In the largest U.S. registry of measured treadmill VO2 max, the median (50th percentile) for men falls from 48.0 ml/kg/min in their 20s to 37.8 in their 40s and 24.4 in their 70s; for women it falls from 37.6 to 26.7 to 18.3 over the same decades (Kaminsky et al., 2015). If your value sits above the 75th percentile for your age and sex, you are well above typical for that sample. Above the 90th, you are in the top tenth of that sample.

The chart below comes from that paper. After it, we cover how to estimate your own number without a lab, why your watch shows something different, and why the number tells you less than it seems to.

VO2 max chart by age and gender (FRIEND registry)

FRIEND (Fitness Registry and the Importance of Exercise National Database) pooled 7,783 maximal treadmill tests from eight U.S. laboratories between January 2014 and February 2015. Every test measured respiratory gases directly. Participants were aged 20–79 and free of known cardiovascular disease, and a test counted as maximal at a respiratory exchange ratio of 1.0 or higher (Kaminsky et al., 2015).

All values are in ml/kg/min, transcribed from Table 3 of the paper.

Men: measured treadmill VO2 max percentiles

Age 5th 10th 25th 50th 75th 90th 95th
20–29 29.0 32.1 40.1 48.0 55.2 61.8 66.3
30–39 27.2 30.2 35.9 42.4 49.2 56.5 59.8
40–49 24.2 26.8 31.9 37.8 45.0 52.1 55.6
50–59 20.9 22.8 27.1 32.6 39.7 45.6 50.7
60–69 17.4 19.8 23.7 28.2 34.5 40.3 43.0
70–79 16.3 17.1 20.4 24.4 30.4 36.6 39.7

Women: measured treadmill VO2 max percentiles

Age 5th 10th 25th 50th 75th 90th 95th
20–29 21.7 23.9 30.5 37.6 44.7 51.3 56.0
30–39 19.0 20.9 25.3 30.2 36.1 41.4 45.8
40–49 17.0 18.8 22.1 26.7 32.4 38.4 41.7
50–59 16.0 17.3 19.9 23.4 27.6 32.0 35.9
60–69 13.4 14.6 17.2 20.0 23.8 27.0 29.4
70–79 13.1 13.6 15.6 18.3 20.8 23.1 24.1

Source: Kaminsky LA, Arena R, Myers J. Mayo Clinic Proceedings 2015;90(11):1515–1523, Table 3 (FRIEND rows).

Three things to know before you read your row

  1. These are percentiles of one lab sample, not a fitness grade. The 50th percentile is the middle of people who took a lab treadmill test at those eight centers. It is not a target, and it is not a population-wide health threshold.
  2. The 2022 update is lower. A later FRIEND analysis drew on 34 U.S. labs and included 16,278 treadmill tests from adults aged 20–89. Its treadmill reference values came out 1.5–4.6 ml/kg/min lower than the 2015 standards, and the authors describe it as more representative of the U.S. population (Kaminsky et al., 2022). We could not access that paper’s full percentile table, so we have not reproduced it. In practice, the same VO2 max ranks somewhat higher against the 2022 norms than against the table above.
  3. The decline with age is steady. The 2015 authors report about 10% per decade across five decades. The 2022 update reports an average of 13.5%, or 4.0 ml/kg/min, per decade for treadmill tests.

The same Table 3 also lists Cooper Clinic values. Those were predicted from Balke treadmill time rather than measured with gas analysis, and they run noticeably higher than FRIEND in older age groups. When you see a “VO2 max by age” chart online, check whether it uses measured or predicted values before comparing yourself to it.

What is a good VO2 max for my age?

A useful way to read the chart:

  • Below the 25th percentile: lower than three-quarters of that age-and-sex group in the lab sample.
  • 25th–75th percentile: the middle half of the sample.
  • Above the 75th: clearly above typical.
  • Above the 90th: the top tenth. Trained endurance athletes often test here, but the paper does not report training status.

For example, a 45-year-old man at 45.0 ml/kg/min sits right at the 75th percentile for his decade. The same 45.0 would put a 25-year-old man between the 25th and 50th, and a 45-year-old woman above the 95th.

Treat this as context, not a diagnosis. Cardiorespiratory fitness is strongly linked to health outcomes in the research literature. But a percentile from a field estimate is not a clinical assessment. If you have symptoms or a heart or lung condition, or you are unsure whether a maximal test is safe for you, talk to a clinician first.

How to estimate VO2 max without a lab

The VO2 max calculator offers three published field methods. Each one turns a different observation into an estimate of ml/kg/min.

Cooper 12-minute run

You run as far as you can in exactly 12 minutes on a measured, flat course. The calculator then applies (meters − 504.9) ÷ 44.73. Cooper’s 1968 study compared 12-minute distance with treadmill oxygen uptake in 115 U.S. Air Force officers and airmen (Cooper, 1968; protocol background from The Cooper Institute).

The study’s comparison table covered 1.090 to 2.000 miles. To respect that range, the calculator refuses distances under about 1,754 m and flags anything past 3,218.7 m (2 miles) as an extrapolation.

12-min distance (m) Yards Miles Estimated VO2 max (ml/kg/min)
1,800 1,969 1.12 29.0
2,000 2,187 1.24 33.4
2,200 2,406 1.37 37.9
2,400 2,625 1.49 42.4
2,600 2,843 1.62 46.8
2,800 3,062 1.74 51.3
3,000 3,281 1.86 55.8
3,200 3,500 1.99 60.3

Computed with the Endurance Toolbox VO2 max calculator using the Cooper equation.

Each extra 100 m in 12 minutes adds about 2.2 ml/kg/min. That is why a windy day or a sloppy course measurement can noticeably change your result.

Uth heart-rate ratio

This method needs no run at all, only two numbers: 15.3 × (maximum HR ÷ resting HR). It was developed in 46 well-trained men aged 21–51. In the 36-man validation group, the standard error was 2.7 ml/kg/min, about 4.5%. When an age-predicted maximum heart rate replaced a measured one, the error rose to 4.7 ml/kg/min. The authors state that whether it works for other groups still needs direct validation (Uth et al., 2004).

So use a maximum HR you have actually measured, and treat results for women, older adults, and untrained people as rougher.

The calculator also supports a 1.5-mile time trial (483 ÷ minutes + 3.5). The examples below use the two methods above.

Two worked examples

Example 1: a 45-year-old woman runs the Cooper test. She covers 2,200 m (2,406 yd) in 12 minutes on a track. Entering 2,200 m gives 37.9 ml/kg/min (Cooper equation). On the FRIEND women’s 40–49 row, that falls between the 75th percentile (32.4) and the 90th (38.4).

One caveat: Cooper validated the test in Air Force personnel, not middle-aged women, and her number is an estimate while the FRIEND row is measured. A fair reading is “comfortably above typical for her age group in that sample”, not “88th percentile”.

Example 2: a 38-year-old man uses the heart-rate ratio. His highest heart rate from a recent all-out hill effort was 185 bpm, and his morning resting HR averages 50 bpm. The ratio is 3.70, and 15.3 × 3.70 gives 56.6 ml/kg/min. That sits just above the 90th percentile (56.5) on the FRIEND men’s 30–39 row.

He fits the Uth study population (trained man, age 21–51). Even so, ±2.7 ml/kg/min spans from between the 75th and 90th percentiles up to just under the 95th. A small change in resting HR also moves the result a lot: at 55 bpm instead of 50, the same formula gives 51.5.

VO2 max vs VDOT: a race-performance proxy

If you run, the VDOT calculator is often more useful than a VO2 max estimate. VDOT is not lab VO2 max. Jack Daniels’ model takes a race result, works out the oxygen cost of running at that speed, and divides by the share of VO2 max a runner can sustain for that duration.

So VDOT mixes aerobic capacity with running economy, lactate threshold, and how well you pace a race. Two runners with the same lab VO2 max can have very different VDOTs.

5K time VDOT
20:00 49.8
22:00 44.5
25:00 38.3
30:00 30.8

Computed with the Endurance Toolbox VDOT calculator using Daniels’ oxygen-cost and %VO2max equations, rounded to 0.1.

Take the man from Example 2, whose heart-rate-ratio estimate was 56.6. If his current 5K is 20:00, his VDOT is 49.8. Neither number is wrong. They answer different questions. VDOT describes what he can do in a race and sets his training paces. The VO2 max figure estimates the ceiling of his aerobic engine. For pace decisions, trust the race.

Why your smartwatch VO2 max is different

Watch makers estimate VO2 max with proprietary models. Typically these relate heart rate to running speed or cycling power during ordinary workouts, combined with your profile data. None of them measure oxygen.

They can disagree with a field test, or with each other, for predictable reasons:

  • Maximum heart rate setting: an age-predicted default instead of a measured value. The Uth study shows how much that one substitution can widen the error.
  • Wrist optical HR: lag or cadence lock during intervals.
  • GPS or pace errors: on trails, under trees, or among tall buildings.
  • Heat, hills, and fatigue: all raise heart rate at a given pace.
  • Proprietary methods: the algorithms are not public, so you can’t check who they were validated on.

A watch is most useful for its trend under similar conditions, not its absolute value against a lab chart.

Limitations

  • Field estimates ≠ measured values. The FRIEND percentiles come from gas-analysis treadmill tests, while the Cooper, 1.5-mile, and Uth outputs are regression estimates. Comparing one to the other mixes methods, so read your percentile as approximate.
  • Narrow source populations. Cooper’s validation used 115 Air Force personnel. Uth’s came from well-trained men aged 21–51. Accuracy outside those groups has not been established by the original studies.
  • Measurement mode matters. Treadmill VO2 max typically runs higher than cycle-ergometer VO2 max, and FRIEND publishes separate cycling norms. Cyclists comparing a bike-based number to this chart will look worse than they are.
  • Sample, not population. FRIEND 2015 drew on people tested at eight U.S. labs and had only 137 men and 98 women aged 70–79. The 2022 update widened coverage and lowered the treadmill norms.
  • Relative units penalize body mass. ml/kg/min falls when weight rises even if the heart and lungs have not changed.
  • Maximal tests are strenuous. They are not appropriate for everyone without medical clearance.

How to use the calculators

  1. Open the VO2 max calculator and pick a method.

    • Cooper: enter your 12-minute distance in meters or yards.
    • 1.5-mile: enter your finish time.
    • Uth HR ratio: enter your measured maximum HR and your resting HR.

    You get an estimate in ml/kg/min, plus a warning if a Cooper distance falls outside the original study’s range. Find your age and sex row above to see roughly where you sit.

  2. If you race, enter a recent race distance and time in the VDOT calculator. You get a VDOT score, equivalent times for other distances, and training paces.

  3. To turn fitness into day-to-day intensity, put your maximum and resting HR into the HR zone calculator for heart-rate-reserve or max-HR zones. Zone 2 heart rate: 5 methods compared explains why those methods give different numbers.

When you retest, use the same protocol and similar conditions. A consistent method shows real change better than any single number on a chart.