Estimate your cardiorespiratory fitness using multiple test methods
Walk 1 mile (1.609 km) as fast as possible, then immediately record your heart rate.
Uses your resting heart rate to estimate VO2 max via the Uth-Sørensen-Overgaard-Pedersen formula.
Enter your measured or estimated maximum heart rate and resting heart rate to use the heart rate reserve method.
Choose your preferred test method from the tabs above, fill in the required fields, and click "Calculate VO2 Max." The Cooper 12-minute run and Rockport walk test require you to physically perform a timed effort, while the resting heart rate and max heart rate methods use only physiological measurements.
Your result is displayed in mL/kg/min — the standard unit for VO2 max — along with your fitness category, a color-coded scale, and a comparison table showing norms for your age and sex.
VO2 max is the single best predictor of cardiovascular health and long-term longevity — more predictive than blood pressure, cholesterol, or BMI for all-cause mortality risk. A landmark study in JAMA found that individuals in the bottom 25% of cardiorespiratory fitness had a mortality risk 5× higher than those in the top 25%.
Practically: a 35-year-old male with a VO2 max of 35 mL/kg/min struggles with brisk hiking and tires quickly on stairs. The same person improving to 50 mL/kg/min — very achievable with 6–12 months of consistent training — can comfortably run a 5K, cycle for hours, and maintain energy all day. Elite marathon runners typically score 70–85; Tour de France cyclists often exceed 90.
VO2 max also guides training intensity — coaches use it to set heart rate zones, pacing strategies, and identify overtraining before it causes injury.
Cooper 12-Minute Run (most accurate field test):
VO2 max = (distance_meters − 504.9) / 44.73
Rockport 1-Mile Walk Test:
VO2 max = 132.853 − (0.0769 × weight_lbs) − (0.3877 × age) + (6.315 × sex_m) − (3.2649 × time_min) − (0.1565 × HR)
Resting HR Method (Uth-Sørensen-Overgaard-Pedersen formula):
VO2 max = 15 × (HRmax / HRrest)
Max HR Reserve Method:
VO2 max = 15.3 × (HRmax / HRrest)
It varies significantly by age and sex. A 30-year-old male scoring above 52 mL/kg/min is in the "excellent" range; a 30-year-old female above 45 mL/kg/min is similarly excellent. VO2 max typically peaks in the late 20s and declines ~1% per year after 25–30 in sedentary individuals — but active people maintain much higher values much longer.
Field tests carry an error margin of approximately ±10–15% compared to laboratory VO2 max measurements (gold standard: graded treadmill/cycle test with metabolic gas analysis). The Cooper run is most accurate for athletes; the Rockport test works well for sedentary or older adults. Resting HR methods are the least precise but require no physical test.
Yes — and significantly. High-intensity interval training (HIIT) and long slow distance (LSD) cardio both improve VO2 max. Research shows 4×4-minute intervals at ~90–95% max heart rate (the "Norwegian method") produces some of the largest VO2 max improvements. Sedentary beginners can gain 15–20%; trained athletes typically gain 3–8% per training block.
If you can run, use the Cooper 12-minute run — it's the most validated field test. If you're older, overweight, or new to exercise, the Rockport walk test is safer and still reasonably accurate. Use the resting heart rate method for a quick baseline without any physical effort. The max HR method works well if you know your true maximum from a hard race or test.