Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
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.
Fill in the required fields to see your result.
Fitness
VO2 Max Calculator
Estimate your VO2 max — the maximum rate at which your body can take up and use oxygen during exhaustive exercise — from a recent race time without needing a lab treadmill or metabolic cart. VO2 max is the single best whole-system measure of aerobic fitness and is strongly predictive of all-cause mortality.
Fill in the required fields to see your result.
Key differences
| Heart Rate Training Zones Calculator | VO2 Max Calculator | |
|---|---|---|
| Category | Fitness | Fitness |
| Inputs required | 4 | 4 |
| Result | Zone 3 Target HR (bpm) | Estimated VO2 Max (ml/kg/min) |
| What it does | 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. | Estimate your VO2 max — the maximum rate at which your body can take up and use oxygen during exhaustive exercise — from a recent race time without needing a lab treadmill or metabolic cart. VO2 max is the single best whole-system measure of aerobic fitness and is strongly predictive of all-cause mortality. |