1. Your profile
Age and sex are used for the Rockport test and the ACSM classification. Weight is needed only for Rockport.
2. Enter your test results
Complete any methods you have data for — one is enough, two or more unlock the agreement analysis.
Cooper 12-minute run test (1968)
Run as far as you can in exactly 12 minutes on a flat course. Enter the total distance. This Cooper test calculator implements the classic 12 minute run test formula.
VO₂max = (distancem − 504.9) / 44.731.5-mile run test (US Navy)
Run 1.5 miles (2.4 km) as fast as possible. Enter your finish time.
VO₂max = 3.5 + 483 / timeminRockport 1-mile walk test (Kline et al.)
Walk one mile as fast as you can (no running), on flat ground — a submaximal walking test ideal when a hard run is not advisable. Record your time and heart rate at the finish. Uses your profile weight, age, and sex above.
VO₂max = 132.853 − 0.0769·lb − 0.3877·age + 6.315·sex − 3.2649·min − 0.1565·HRUth heart-rate ratio (Uth et al., 2004)
No exercise needed — just your maximum and resting heart rates.
VO₂max = 15.3 × (HRmax / HRrest)VDOT calculator from race performance (Jack Daniels)
Enter a recent race result — this VDOT calculator back-calculates your score with Daniels' published equations.
3. Results
Your comparison will appear here.
VO₂ max norms by age and gender (ACSM / Cooper Institute)
Find your age band and read across. Values are ml/kg/min. The calculator above grades each result against this table automatically.
Men
| Age | Superior | Excellent | Good | Fair | Poor |
|---|---|---|---|---|---|
| 20–29 | ≥ 55.4 | 51.1 – 55.3 | 45.4 – 51.0 | 41.7 – 45.3 | < 41.7 |
| 30–39 | ≥ 54.0 | 48.3 – 53.9 | 44.0 – 48.2 | 40.5 – 43.9 | < 40.5 |
| 40–49 | ≥ 52.5 | 46.4 – 52.4 | 42.4 – 46.3 | 38.5 – 42.3 | < 38.5 |
| 50–59 | ≥ 48.9 | 43.4 – 48.8 | 39.2 – 43.3 | 35.6 – 39.1 | < 35.6 |
| 60–69 | ≥ 45.7 | 39.5 – 45.6 | 35.5 – 39.4 | 32.3 – 35.4 | < 32.3 |
| 70–79 | ≥ 42.1 | 36.7 – 42.0 | 32.3 – 36.6 | 29.4 – 32.2 | < 29.4 |
Women
| Age | Superior | Excellent | Good | Fair | Poor |
|---|---|---|---|---|---|
| 20–29 | ≥ 49.6 | 43.9 – 49.5 | 39.5 – 43.8 | 36.1 – 39.4 | < 36.1 |
| 30–39 | ≥ 47.4 | 42.4 – 47.3 | 37.8 – 42.3 | 34.4 – 37.7 | < 34.4 |
| 40–49 | ≥ 45.3 | 39.7 – 45.2 | 36.3 – 39.6 | 33.0 – 36.2 | < 33.0 |
| 50–59 | ≥ 41.1 | 36.7 – 41.0 | 33.0 – 36.6 | 30.1 – 32.9 | < 30.1 |
| 60–69 | ≥ 37.8 | 33.0 – 37.7 | 30.0 – 32.9 | 27.5 – 29.9 | < 27.5 |
| 70–79 | ≥ 36.7 | 30.9 – 36.6 | 28.1 – 30.8 | 25.9 – 28.0 | < 25.9 |
Normative data: The Cooper Institute for Aerobics Research (percentile-based cardiorespiratory fitness classifications), as used in ACSM-aligned references. Ages under 20 or over 79 are graded against the nearest published band, noted in the result.
Methodology & honest scope
The five formulas
- Cooper 12-min (Cooper, 1968): VO₂max = (distance in meters − 504.9) / 44.73.
- 1.5-mile run (US Navy): VO₂max = 3.5 + 483 / time in minutes.
- Rockport 1-mile walk (Kline et al.): 132.853 − 0.0769 × weight(lb) − 0.3877 × age + 6.315 × sex(1/0) − 3.2649 × time(min) − 0.1565 × HR.
- Uth HR-ratio (Uth et al., 2004): VO₂max = 15.3 × (HRmax / HRrest). HRmax may be measured or estimated with Tanaka (208 − 0.7 × age) or 220 − age.
- VDOT (Jack Daniels): oxygen cost = −4.60 + 0.182258 × v + 0.000104 × v² (v in m/min, Daniels & Gilbert); sustainable fraction = 0.8 + 0.1894393·e^(−0.012778·t) + 0.2989558·e^(−0.1932605·t) (t in min); VDOT = oxygen cost / fraction.
What these numbers can and cannot do
Honest scope: every method here is an estimate, typically within ±10–15% of a laboratory test with a metabolic cart. Lab testing remains the gold standard. Results are for fitness tracking and training guidance — not diagnosis, not medical advice. Maximal tests are strenuous: get medical clearance first if you have cardiac risk factors, and stop immediately with chest pain, dizziness, or severe breathlessness.
Different methods legitimately disagree by a few points because they measure different things (running economy vs. walking efficiency vs. cardiac size vs. race performance). That is why this tool compares them instead of pretending one number is the truth.
Privacy
All computation happens in your browser. No data is sent anywhere — the page works fully offline once loaded.
VO₂ max — frequently asked questions
What is VO2 max?
VO2 max is the maximum rate at which your body can consume oxygen during intense exercise, measured in milliliters of oxygen per kilogram of body weight per minute (ml/kg/min). It is the gold-standard single number for cardiorespiratory fitness: a higher VO2 max means your heart, lungs, and muscles deliver and use oxygen more efficiently. This calculator estimates it with five published test methods side-by-side.
How accurate are VO2 max calculators?
Field-test estimates are typically within about 10–15% of a laboratory measurement. A lab test with a metabolic cart while running to exhaustion on a treadmill remains the gold standard. Treat every calculator result — including this one — as an estimate, not a medical measurement. Comparing several methods at once (as this tool does) gives a more honest picture than trusting any single formula.
How do I perform the Cooper 12-minute test?
Warm up thoroughly, then run as far as you can in exactly 12 minutes on a flat track or treadmill — pace yourself, it is not a sprint. Record the total distance in meters and enter it above. The formula is VO2max = (distance in meters − 504.9) / 44.73. For example, 3,000 m in 12 minutes estimates about 55.8 ml/kg/min.
How do I perform the Rockport 1-mile walk test?
Walk one mile (1,609 m) as fast as you can without running, on flat ground. Time yourself and take your heart rate immediately at the finish. Enter your weight, age, sex, walk time, and finishing heart rate. The Kline et al. equation converts these into a VO2 max estimate. Because it is submaximal, it is the safest option here for beginners or anyone with cardiac risk factors — but check with a doctor first if you have any concerns.
What is the 1.5-mile run test protocol?
After a warm-up, run 1.5 miles (2.4 km) as fast as you can and record your time. The US Navy formula is VO2max = 3.5 + 483 / time-in-minutes. A 12:00 1.5-mile estimates about 43.8 ml/kg/min. It is a maximal test, so only attempt it if you are already trained and healthy.
What is VDOT (Jack Daniels)?
VDOT is a single fitness score from exercise physiologist Jack Daniels that predicts equivalent race performances across distances. This calculator derives it from any recent race result using Daniels' published equations: oxygen cost from running velocity, divided by the fraction of VO2 max sustainable for that duration. A 5K in 20:00 gives a VDOT of about 49.8. VDOT doubles as a training-pace anchor in Daniels' Running Formula.
What is the Uth HR-ratio method?
Published by Uth et al. (2004), it estimates VO2 max as 15.3 × (HRmax / HRrest) — no exercise test required, just your maximum and resting heart rates. It works because a bigger stroke volume shows up both as a lower resting heart rate and a higher oxygen uptake. Use a measured HRmax when possible; otherwise the tool can estimate it with the Tanaka (208 − 0.7 × age) or classic (220 − age) equations.
What is a good VO2 max for my age and gender (VO2 max by age chart)?
Use the ACSM/Cooper Institute VO2 max by age chart on this page: enter your age and sex and every result is graded Superior, Excellent, Good, Fair, or Poor against population norms. As a rough guide, for men aged 20–29 above 55.4 is Superior and below 41.7 is Poor; for women aged 20–29 above 49.6 is Superior and below 36.1 is Poor. Norms decline with age, which is normal.
What is the Åstrand test?
The Åstrand-Rhyming test is a classic submaximal cycle-ergometer protocol: pedal 6 minutes at a fixed workload, record steady-state heart rate, and read VO2 max from the Åstrand nomogram with an age correction factor. It needs a stationary bike with adjustable resistance, which is why this calculator focuses on run/walk/HR methods you can do with just a stopwatch — but the Åstrand test remains a respected lab-adjacent option.
Can I estimate VO2 max without a hard running test?
Yes. The Rockport 1-mile walk test is submaximal (brisk walking only), and the Uth HR-ratio method needs no exercise at all — just resting and maximum heart rate. Both are reasonable when you are untrained, returning from injury, or advised to avoid maximal efforts. They are slightly less precise than the Cooper or 1.5-mile tests, which the agreement panel will show.
Why do the five methods give different numbers?
Each protocol stresses the body differently: the Cooper test rewards running economy, Rockport leans on walking efficiency and heart-rate response, Uth reflects cardiac size via heart-rate ratio, and VDOT is back-calculated from race performance. A spread of a few points is normal. If one method is a clear outlier, retest that protocol — pacing errors are the most common cause.
What is the difference between VO2 max and VDOT?
VO2 max is a physiological quantity (ml/kg/min). VDOT is Jack Daniels' performance score derived from race times — numerically close to VO2 max for most runners, but conceptually it is 'the VO2 max value that best explains your race result.' Use VDOT to set training paces; use VO2 max estimates to track fitness changes over time.
How often should I retest my VO2 max?
Every 6–12 weeks is plenty. VO2 max responds to training on that timescale, and testing more often mostly measures noise, pacing variation, and daily form. Keep conditions similar between tests: same course, similar weather, similar warm-up, and a rested state.
How can I improve my VO2 max?
The best-supported methods are high-intensity interval training (e.g., 4×4-minute intervals near max heart rate with active recovery), tempo/threshold runs, and simply increasing consistent aerobic volume. Most beginners see rapid gains in 8–12 weeks. Increase intensity gradually and include easy days — overtraining stalls progress and invites injury.
Is VO2 max testing safe? Do I need to see a doctor?
Maximal tests (Cooper, 1.5-mile) are strenuous by design. If you have a heart condition, chest pain, dizziness, very high blood pressure, or are over 40 and sedentary, talk to a doctor before attempting one — the submaximal Rockport walk or the no-exercise Uth method are safer starting points. Stop any test immediately if you feel chest pain, severe breathlessness, or lightheadedness. Nothing on this page is medical advice.
Is my data private? Does this tool send anything anywhere?
Yes, fully private. This calculator runs 100% in your browser — your age, weight, heart rates, and results never leave your device. There are no accounts, no analytics beacons, and no external requests; you can verify by disconnecting from the internet and watching it still work.