VO₂max & heart rate zone calculator
Two answers from the same three numbers. VO₂max is the best single measure of aerobic fitness, estimated here from your maximum and resting heart rate. The same inputs give your five training zones, fitted to your fitness with the Karvonen method.
VO2 Max & Heart Rate Zone Calculator
VO₂max can be estimated as 15.3 × (maximum heart rate / resting heart rate), with maximum heart rate approximated by 208 − 0.7 × age. For a man in his thirties, 44 ml/kg/min and above is good and 49 is excellent; for a woman the same bands sit near 37 and 41. The same heart rates set the five training zones: zone 2, the easy aerobic zone, is 60 to 70 percent of heart-rate reserve above resting.
Measured seated or lying, ideally first thing in the morning.
Leave blank to estimate it from your age.
Excellent
Training zones · Karvonen
Method notes (4)
- Estimated from the resting/max heart-rate ratio (Uth 2004) — a no-effort proxy. A graded treadmill or bike test measures VO₂max directly and more accurately.
- Accuracy hinges on a true resting heart rate: measure it seated or lying down after a few minutes of quiet, ideally first thing in the morning.
- Max heart rate estimated as 186 bpm (Tanaka: 208 − 0.7 × age). Provide a measured HRmax for a tighter estimate.
- Category boundaries are population reference ranges by age and sex (Cooper/ACSM-style), not clinical cutoffs — use the trend over time more than the single label.
runs the same code as the app · nothing is sent anywhere
How it works
The Uth-Sørensen-Overgaard-Pedersen estimate: VO₂max ≈ 15.3 × (HRmax / HRrest). When you do not supply a measured maximum heart rate it is estimated with Tanaka's equation, HRmax ≈ 208 − 0.7 × age, which tracks the general population better than the old 220 minus age rule.
Everything hinges on a genuine resting heart rate. Measure it seated or lying after several minutes of quiet, ideally before getting out of bed. A reading taken after coffee or a walk to the kitchen will flatter or penalise you by a wide margin.
The reference bands are Cooper Institute and ACSM-style population norms by age and sex. They are reference ranges, not clinical thresholds.
The training zones use Karvonen: bpm = HRrest + % × (HRmax − HRrest), with bands at 50–60, 60–70, 70–80, 80–90 and 90–100 percent of heart-rate reserve. Working from reserve rather than a straight percentage of max means two people of the same age but different fitness get different zones.
Common questions
What is a good VO2 max?
For a man in his thirties, roughly 44 and above is good and 49 and above is excellent; for a woman the same bands sit near 37 and 41. Endurance athletes commonly exceed 60.
How accurate is the heart-rate method?
It is a proxy, not a measurement, and it is least reliable at the extremes. A graded treadmill or bike test measures VO2 max directly. Use this to track your own trend rather than to compare against someone else.
How do I raise it?
A mix of long easy aerobic work and short hard intervals. The resting heart rate falling over weeks is the signal that the estimate will follow.
What is zone 2 training?
Easy aerobic work at 60 to 70 percent of heart-rate reserve, a pace you could hold a conversation at. It builds the aerobic base and is where endurance athletes spend most of their training time.
Should I use 220 minus age for max heart rate?
Tanaka's 208 − 0.7 × age fits the population better, especially past 40, where 220 − age reads too low. Either way an individual's real max can be 10 bpm either side, so a measured max from a hard effort beats any formula.
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