Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Fitness
VO2 Max Estimator (Resting Heart Rate)
Estimates your VO2 max — the maximum amount of oxygen your body can use during intense exercise — from your resting heart rate and age, with no treadmill test required. It uses the Uth–Sørensen heart-rate-ratio method, a quick proxy for cardiorespiratory fitness.
Fitness
Heart Rate Training Zones Calculator
Calculate your personalised heart rate training zones using the Karvonen heart rate reserve method, which factors in resting heart rate to give zones that actually reflect your cardiovascular fitness. Used by coaches and endurance athletes to keep aerobic, threshold, and VO2-max sessions in the right intensity bands.
Key differences
| VO2 Max Estimator (Resting Heart Rate) | Heart Rate Training Zones Calculator | |
|---|---|---|
| Category | Fitness | Fitness |
| Inputs required | 2 | 4 |
| Result | Estimated VO2 Max (ml/kg/min) | Zone 3 Target HR (bpm) |
| What it does | Estimates your VO2 max — the maximum amount of oxygen your body can use during intense exercise — from your resting heart rate and age, with no treadmill test required. It uses the Uth–Sørensen heart-rate-ratio method, a quick proxy for cardiorespiratory fitness. | Calculate your personalised heart rate training zones using the Karvonen heart rate reserve method, which factors in resting heart rate to give zones that actually reflect your cardiovascular fitness. Used by coaches and endurance athletes to keep aerobic, threshold, and VO2-max sessions in the right intensity bands. |