Know your aerobic fitness — no lab required
Estimation Method
Heart Rate Inputs
Measure after waking, before getting up.
Best measured from a max-effort test. If blank, the Tanaka formula (208 − 0.7 × age) is used.
Your VO2 Max
VO2 Max Rating Chart (ml/kg/min)
| Category | Males (30–39) | Females (30–39) |
|---|---|---|
| Poor | < 31 | < 22 |
| Fair | 31–35 | 22–26 |
| Average | 35–41 | 26–33 |
| Good | 41–49 | 33–39 |
| Excellent | 49–53 | 39–43 |
| Superior | ≥ 53 | ≥ 43 |
Source: ACSM Guidelines for Exercise Testing and Prescription. Values vary by age group — see ACSM tables for full breakdown.
How these estimates work: The Heart Rate method uses the Uth–Sørensen formula (VO2max = 15 × HRmax/HRrest), validated in healthy adults. The 1-Mile Walk Test uses the Rockport formula (Kline et al., 1987) when end-of-walk heart rate is provided, otherwise a Cooper time-based estimate. These are non-exercise estimates — a lab VO2 max test remains the gold standard. Results are for informational purposes only.
VO2 max is the gold-standard measure of aerobic fitness — the maximum rate at which your body can consume oxygen during exercise. Our free VO2 max calculator estimates your score in seconds using either the Uth–Sørensen heart-rate formula (resting and max HR) or the validated Rockport 1-Mile Walk Test. Get your ml/kg/min score, fitness category, and a comparison against ACSM norms.
VO2 max (maximal oxygen uptake) measures how efficiently your cardiovascular system delivers oxygen to working muscles. Higher values indicate better aerobic endurance and are strongly linked to long-term health outcomes, including lower risk of heart disease and all-cause mortality.
Both are non-exercise field estimates, so neither rivals a lab test. The Rockport 1-Mile Walk formula (Kline et al., 1987) tends to be slightly more accurate because it incorporates your heart-rate response. The Uth–Sørensen heart-rate formula is convenient if you know your resting HR and either measured or age-predicted max HR.
Measure it first thing in the morning before getting out of bed. Sit quietly for one to two minutes, then count your pulse for 60 seconds (or 30 seconds × 2). A typical resting HR is 60–80 bpm; well-trained athletes often sit at 40–60 bpm.
It varies by age and sex. For a 30-year-old male, above 49 ml/kg/min is Excellent; for a 30-year-old female, above 39 is Excellent. Elite endurance athletes commonly exceed 70 (men) or 60 (women). The ACSM rating table included in the calculator shows norms for each age group.