🎯 Target Heart Rate Calculator
Determine training heart rate zones to match workout goals—fat burning, endurance, or high-intensity intervals.
If unknown, we use 208 − 0.7×Age.
Get a personalized target zone.
Estimated Max HR
184 bpm
Predicted (Tanaka): 184 bpm
Resting HR
60 bpm
Reserve: 124 bpm
Custom Target
153 bpm
75% intensity (Karvonen) / 138 bpm (% max)
| Zone | Intensity % | Karvonen HR (bpm) | % Max HR Range |
|---|---|---|---|
| Warm-Up | 50–60% | 122 – 134 bpm | 92 – 110 bpm |
| Fat Burning / Easy | 60–70% | 134 – 146 bpm | 110 – 128 bpm |
| Aerobic / Moderate | 70–80% | 146 – 159 bpm | 128 – 147 bpm |
| Anaerobic / Hard | 80–90% | 159 – 171 bpm | 147 – 165 bpm |
| VO₂ Max / Very Hard | 90–95% | 171 – 177 bpm | 165 – 174 bpm |
How to Use This Calculator
Measure resting heart rate
Count beats at rest (morning) for 60 seconds.
Enter age and HR data
Provide observed max HR if available, otherwise we estimate.
Review training zones
Check both % max and Karvonen heart rate ranges for each zone.
Set intensity targets
Use the custom intensity field to target a specific effort level.
Formula
Predicted Max HR = 208 − 0.7 × Age
Karvonen Target HR = Rest + (Max − Rest) × Intensity
% Max Target HR = Max × Intensity
Use the Karvonen formula for personalized zones based on heart rate reserve (difference between max and resting heart rate). % max HR provides a simpler approach widely used in fitness classes and wearables.
Example
Age 40, resting HR 55, estimated max 180 → Zone 3 (70–80% HRR) = 55 + 125 × 0.70 = 143 bpm to 55 + 125 × 0.80 = 155 bpm. % Max equivalent: 126–144 bpm.
Variables
- Age: Predict max HR when not supplied
- Resting HR: Morning heart rate
- Max HR: Observed or predicted highest heart rate
- Intensity: Desired training percentage
Using Target Heart Rates Effectively
Heart rate zones guide cardio training intensity, ensuring sessions support specific goals like fat loss, endurance, or speed. Combine HR data with perceived exertion and power/pace for comprehensive feedback.
Training Tips
- Use Zone 2 for long aerobic sessions and recovery days.
- Train in Zone 4 once or twice weekly to improve threshold.
- Monitor heart rate drift—if HR rises at same pace, focus on aerobic conditioning.
Safety & Adjustments
- Hydration, temperature, and fatigue affect heart rate response.
- Chest straps provide more accurate readings than wrist sensors.
- If on heart rate–altering medications, consult a clinician for personalized targets.
Frequently Asked Questions
Do I need a lab test to know my max HR?
No. Field tests (progressive intervals) or predicted formulas are sufficient for most people, but lab tests improve accuracy if available.
Why are my heart rate zones different from my wearable?
Wearables use proprietary algorithms; compare outputs and adjust based on your actual performance and fatigue levels.
Can I target multiple zones in one workout?
Yes. Interval sessions intentionally move through warm-up, working, and cool-down zones.
How frequently should I update resting HR?
Check monthly or when training load changes. Lower resting HR often indicates improved fitness.
What if I feel dizzy at target heart rate?
Stop immediately and seek medical advice. Heart rate targets should feel challenging but manageable when healthy.