Target Heart Rate Calculator
Calculate target heart rate zones for fat burn, cardio, and peak training from age and resting HR.
Returns 5 BPM zones using the Karvonen formula.
Target heart rate zones help you exercise at the right intensity for your fitness goals. This calculator supports two methods: the standard percentage-of-max method and the more accurate Karvonen method.
Standard Method:
Maximum Heart Rate (MHR) = 220 - Age
Target HR = MHR × Intensity %
Karvonen Method (more accurate when resting heart rate is provided):
Heart Rate Reserve (HRR) = MHR - Resting HR
Target HR = (HRR × Intensity %) + Resting HR
What each variable means:
- Age — your current age in years. MHR decreases with age.
- Resting Heart Rate — your pulse measured first thing in the morning before getting out of bed. Average is 60–80 bpm for adults. Athletes may have 40–60 bpm. Providing this enables the more accurate Karvonen method.
Heart Rate Zones:
| Zone | % of MHR | Purpose |
|---|---|---|
| Zone 1 | 50–60% | Warm-up, recovery, easy walking |
| Zone 2 | 60–70% | Fat burning, base endurance |
| Zone 3 | 70–80% | Aerobic fitness, cardio improvement |
| Zone 4 | 80–90% | Speed training, performance |
| Zone 5 | 90–100% | Maximum effort, short sprints |
Practical example: A 30-year-old with a resting heart rate of 65 bpm. MHR = 220 - 30 = 190. Using the Karvonen method for Zone 3 (70–80%): HRR = 190 - 65 = 125. Lower bound = (125 × 0.70) + 65 = 153 bpm. Upper bound = (125 × 0.80) + 65 = 165 bpm. So the aerobic training zone is 153–165 bpm.
When to use this calculator: Use it to set your target heart rate for cardio workouts, running, cycling, or any aerobic exercise. Staying in the right zone helps you train efficiently without overexertion.
Tips: Most general fitness goals are best served by Zone 2 and Zone 3 training. To measure resting heart rate accurately, take it three mornings in a row and average the results. Wrist-based heart rate monitors on smartwatches are convenient but can be off by 5–10 bpm during intense exercise — chest straps are more accurate.