VO₂max Estimator
Estimate your cardiorespiratory fitness from your resting and max heart rate — using the Uth–Sørensen formula — and see where it lands against age- and sex-based norms.
46.9 ml/kg/min is good — above average cardiorespiratory fitness for men aged 30–39. VO₂max is strongly tied to all-cause mortality, so this is real longevity capital.
Max HR estimated as 184 bpm (Tanaka: 208 − 0.7 × age). Enter your true max HR above for a sharper number.
Educational estimate, not a clinical measurement. The Uth–Sørensen formula approximates a lab VO₂max to within roughly ±10–15%. Accuracy hinges on a true max HR and a resting HR measured first thing in the morning. For a precise value, use a lab test or a maximal field test (Cooper 12-minute run).
Track your fitness trend
ONDA Life turns markers like VO₂max, HRV and resting heart rate into a single readiness picture — so you can see whether your training is actually moving the needle.
Download ONDA Life on the App Store →Sources & methodology
The estimate uses the Heart Rate Ratio Method (Uth–Sørensen 2004): VO₂max ≈ 15.3 × HRmax/HRrest. It needs your true max HR (estimated from age via Tanaka 2001 if you don’t enter one) and an accurate resting HR, ideally measured first thing in the morning. Accuracy is roughly ±10–15% versus a lab test. The fitness categories approximate age- and sex-based percentile bands from the FRIEND registry (Kaminsky 2015) and ACSM norms. VO₂max declines about 10% per decade after 30 without training. For a precise number, a lab CPET or a maximal field test (Cooper 12-minute run) beats any HR-based estimate.
- [1] Uth N, Sørensen H, Overgaard K, Pedersen PK (2004). Estimation of VO2max from the ratio between HRmax and HRrest — the Heart Rate Ratio Method. European Journal of Applied Physiology, 91(1):111–115.
The estimation formula used here: VO₂max ≈ 15.3 × (HRmax ÷ HRrest).
- [2] Tanaka H, Monahan KD, Seals DR (2001). Age-predicted maximal heart rate revisited. Journal of the American College of Cardiology, 37(1):153–156.
Supplies the HRmax estimate (208 − 0.7 × age) when you do not enter a measured max HR.
- [3] Kaminsky LA, Arena R, Myers J (2015). Reference standards for cardiorespiratory fitness measured with cardiopulmonary exercise testing (FRIEND registry). Mayo Clinic Proceedings, 90(11):1515–1523.
Modern US reference standards for VO₂max by age and sex underpinning the fitness-category bands.
Common questions
Where do these VO₂max numbers come from?
The estimate is the Uth–Sørensen (2004) Heart Rate Ratio Method (VO₂max ≈ 15.3 × HRmax/HRrest), with HRmax from Tanaka (2001) when not measured. The fitness categories approximate age/sex reference standards from the FRIEND registry (Kaminsky 2015) and ACSM. Full citations are in the Sources section on this page. It is a population estimate, accurate to about ±10–15% versus a lab test.
What is VO₂max?
VO₂max is the maximum volume of oxygen your body can use per minute (ml/kg/min) — the single best measure of cardiorespiratory fitness. It reflects how well your heart, lungs and muscles deliver and use oxygen, and it is one of the strongest predictors of longevity and all-cause mortality.
How is VO₂max estimated without a lab test?
This tool uses the Uth–Sørensen formula: VO₂max ≈ 15.3 × (max HR ÷ resting HR). It only needs your max and resting heart rate. A low resting HR (a sign of a fit, efficient heart) raises the estimate. It is a population approximation — accurate to within roughly ±10–15% of a lab measurement.
What is a good VO₂max for my age?
It declines with age and is higher in men on average. For men 30–39, "good" is roughly 41–47 ml/kg/min; for women 30–39, about 34–39. Below those is fair/poor, above is excellent/superior. The norms table on this page breaks it down by age and sex.
How do I improve my VO₂max?
The fastest route is a large aerobic base (Zone 2, conversational cardio) topped with 1–2 weekly high-intensity interval sessions (e.g. 4×4-minute efforts near max). VO₂max is highly trainable — meaningful gains show in 6–8 weeks — but it also declines ~10% per decade after 30 without training.
How accurate is the heart-rate estimate?
It is a convenient approximation, not a measurement. It depends on knowing your true max HR (formulas can be ±10–12 bpm off) and an accurate resting HR (measure it first thing in the morning, lying down). For a precise number, a lab VO₂max test or a maximal field test (Cooper 12-minute run) is better.