VO2 Max Calculator
Estimate your VO2 max from a field test, see your fitness category for your age, and get personalised training guidance to improve it.
VO2 max ranges for your age and sex
Recommended training approach
What is VO2 max and why does it matter?
VO2 max is the maximum volume of oxygen your body can use during intense exercise — expressed in millilitres per kilogram of bodyweight per minute (ml/kg/min). It's the gold standard measure of aerobic fitness and cardiovascular health. A higher VO2 max means a more efficient heart, greater endurance capacity, and — critically — better long-term health outcomes.
Research from a 2018 study in JAMA Network Open following 122,000 adults found that low cardiorespiratory fitness was associated with higher all-cause mortality than smoking, diabetes, or hypertension. Moving from "low" to "moderate" fitness produced a 50% reduction in mortality risk. These are among the strongest health-outcome relationships observed for any modifiable lifestyle factor.
VO2 max reference ranges
VO2 max declines with age and differs by sex, primarily due to differences in cardiac size, haemoglobin levels, and muscle mass. These tables reflect data from the American College of Sports Medicine and similar bodies.
Men (ml/kg/min)
| Age | Poor | Below avg | Average | Good | Excellent |
|---|---|---|---|---|---|
| 20–29 | <33 | 33–36 | 37–44 | 45–52 | >52 |
| 30–39 | <31 | 31–35 | 36–44 | 45–52 | >52 |
| 40–49 | <30 | 30–33 | 34–42 | 43–50 | >50 |
| 50–59 | <26 | 26–30 | 31–38 | 39–46 | >46 |
| 60–69 | <22 | 22–25 | 26–34 | 35–42 | >42 |
| 70+ | <20 | 20–22 | 23–30 | 31–38 | >38 |
Women (ml/kg/min)
| Age | Poor | Below avg | Average | Good | Excellent |
|---|---|---|---|---|---|
| 20–29 | <28 | 28–31 | 32–38 | 39–46 | >46 |
| 30–39 | <27 | 27–30 | 31–37 | 38–44 | >44 |
| 40–49 | <25 | 25–28 | 29–35 | 36–42 | >42 |
| 50–59 | <21 | 21–24 | 25–32 | 33–39 | >39 |
| 60–69 | <18 | 18–21 | 22–29 | 30–36 | >36 |
| 70+ | <16 | 16–19 | 20–26 | 27–33 | >33 |
How to improve your VO2 max
The two most evidence-based approaches for improving VO2 max are Zone 2 aerobic training and high-intensity interval training (HIIT). They work through different mechanisms and complement each other.
Zone 2 training (60–70% max HR)
The foundation of aerobic fitness. Zone 2 increases mitochondrial density, cardiac output, and fat oxidation capacity. Sessions of 45–90 minutes, 3–4 times per week, drive meaningful aerobic base development over 8–16 weeks. The key: you should be able to hold a full conversation throughout — if you can't, you've gone above Zone 2.
HIIT — the 4×4 protocol
Four intervals of 4 minutes at 90–95% max HR, with 3-minute active recovery between each. Warm up for 10 minutes before, cool down for 5–10 minutes after. Limit to 1–2 sessions per week — requires 48 hours of recovery. Research from Norwegian scientists shows this protocol increases VO2 max by 7–10% in 8 weeks in recreationally active adults.
The optimal combination
80% of training time in Zone 2, 20% in high-intensity zones (the polarised model). Most people naturally train in Zone 3 — moderate intensity — which is the least effective zone for either Zone 2 adaptations or HIIT adaptations. Avoiding Zone 3 on easy days and making hard days genuinely hard is the key principle.