VO2 Max Calculator
Estimate your aerobic capacity from heart rate.
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VO2 max is the maximum rate at which your body can use oxygen during exercise — the single best indicator of aerobic fitness. This calculator estimates it from your resting and maximum heart rate, and rates where you sit for your age and sex.
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VO2 Max — The Quick Answer
A simple heart-rate estimate uses the Uth–Sørensen formula: VO₂max ≈ 15 × (max HR ÷ resting HR). A lower resting heart rate and higher max give a higher VO2 max.
Shortcut
VO₂max ≈ 15 × (max HR ÷ resting HR)
Typical VO2 max values (ml/kg/min)
| Fitness level | Men (20–29) | Women (20–29) |
|---|---|---|
| Superior | ≥ 50 | ≥ 44 |
| Excellent | 44–49 | 38–43 |
| Good | 38–43 | 33–37 |
| Fair | 33–37 | 28–32 |
| Below average | < 33 | < 28 |
VO2 max peaks in your 20s and declines gradually with age (faster if you don't train). Endurance training can improve it by 10–20% or more.
How It Works
The Formula
Uth–Sørensen estimate
Formula
VO₂max ≈ 15 × (HRmax ÷ HRrest)
Variables
Maximum heart rate
Your highest attainable rate, estimated as 220 − age or measured in a test.
Resting heart rate
Your heart rate at complete rest. Fit individuals often have 40–60 bpm; lower means a stronger heart.
Maximum oxygen uptake
Millilitres of oxygen used per kilogram of body weight per minute — the gold-standard aerobic fitness measure.
Note: This is an indirect estimate. The most accurate VO2 max measurement is a lab test with a mask and gas analysis, but field tests give closer figures than this quick heart-rate method.
Worked Example: VO2 Max for a 30-Year-Old
Uth–Sørensen heart-rate method, resting HR 50 bpm
Estimate maximum heart rate
220 − 30 = 190 bpm
Take your resting heart rate
50 bpm, measured on waking
Apply the Uth–Sørensen formula
VO2max ≈ 15 × (max HR ÷ resting HR)
Compute the estimate
15 × (190 ÷ 50) = 15 × 3.8 ≈ 57 ml/kg/min
Reference Guide
| Fitness level | Men (20–29) | Women (20–29) |
|---|---|---|
| Superior | 50 and above | 44 and above |
| Excellent | 44–49 | 38–43 |
| Good | 38–43 | 33–37 |
| Fair | 33–37 | 28–32 |
| Below average | below 33 | below 28 |
What Your VO2 Max Means
Reading the number — and how to raise it
VO2 max norms shift with age and sex, so a 'good' figure at 50 is lower than at 25. Use the reference bands for your group rather than chasing an absolute number. Higher generally means greater endurance fitness.
Best for: Benchmarking yourself fairly within your age group
VO2 max responds well to training. From an untrained start, 15–20% improvement over months is realistic with a mix of high-intensity intervals and plenty of easy aerobic volume. There's a genetic ceiling and gains slow as you get fitter, but almost everyone has headroom.
Best for: Setting a training goal to improve aerobic capacity
A true VO2 max needs a lab test with a breathing mask. Heart-rate estimates like this are convenient and good for tracking your own trend, but can differ meaningfully from a measured value, so compare with yourself over time rather than against others' lab results. Not medical advice.
Best for: Tracking your own change over time
What Is VO2 Max?
VO2 max is the maximum rate at which your body can take in and use oxygen during intense exercise, measured in millilitres of oxygen per kilogram of body weight per minute (ml/kg/min). It represents the size of your aerobic engine — set by how well your heart, lungs, blood, and muscles deliver and consume oxygen — and it's the single best indicator of cardiovascular fitness, with research also linking higher values to lower mortality risk. A true VO2 max is measured in a lab, but this calculator estimates it from the ratio of your maximum to resting heart rate using the Uth–Sørensen formula, which is handy for tracking change over time.
Key Features
💡 Pro Tips
- →Measure resting heart rate on waking, before any caffeine, for the most accurate estimate — a lower resting rate signals better aerobic fitness.
- →To raise VO2 max, combine high-intensity intervals (hard 3–5 minute efforts) with a large base of easy Zone 2 training.
- →Track the trend over months rather than reading one estimate as precise; this method is best for comparing you against your past self.
- →If you know your true maximum heart rate from a test, enter it — it improves the estimate noticeably over 220 − age.
Common Mistakes
Comparing a heart-rate estimate to someone's lab number
Estimated and lab-measured VO2 max can differ meaningfully. The estimate is best for tracking your own change over time, not for ranking yourself against others' precise lab results.
Assuming VO2 max is fixed
It responds well to training — often 15–20% improvement from an untrained start. There's a genetic ceiling, but believing it can't change is simply wrong for most people.
Using an inaccurate resting or max heart rate
The estimate is a ratio of max to resting HR, so errors in either throw it off. Measure resting HR properly and use a tested max where possible.
Research & Citations
Sources and standards referenced for the factual claims on this page
- [1]
Uth, N., Sørensen, H., Overgaard, K., & Pedersen, P. K. (2004). Estimation of VO2max from the ratio between HRmax and HRrest. European Journal of Applied Physiology, 91(1).
The heart-rate-ratio method this calculator uses.
View source - [2]
American College of Sports Medicine (ACSM) (2021). ACSM's Guidelines for Exercise Testing and Prescription (11th ed.). Wolters Kluwer.
VO2 max norms by age and sex.
View source - [3]
Mandsager, K., et al. (2018). Association of Cardiorespiratory Fitness With Long-term Mortality. JAMA Network Open, 1(6).
Evidence linking higher cardiorespiratory fitness to lower mortality.
View source
This calculator is a reference tool, not a substitute for professional advice. Verify important health, financial, legal, or safety decisions with a suitably qualified professional.
Last updated: October 7, 2026
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Frequently Asked Questions
What is a good VO2 max?
It depends on age and sex. For men in their 20s, 44 ml/kg/min and above is excellent; for women in their 20s, about 38 and above. Values decline with age, so compare against your own age band rather than a single number.
How is VO2 max calculated?
This tool uses the Uth–Sørensen formula: VO2 max ≈ 15 × (max heart rate ÷ resting heart rate). It's a quick estimate based only on heart rate — lab tests are more precise.
Can I improve my VO2 max?
Yes. Endurance training, especially high-intensity intervals, raises VO2 max — often by 10–20% in untrained people within a few months. It naturally declines with age, but training slows that decline.
Why does a low resting heart rate mean better fitness?
A trained heart pumps more blood per beat, so it needs fewer beats at rest. That lower resting rate fits the VO2 max formula as better aerobic fitness — elite endurance athletes often rest in the 30s and 40s.