Target Heart Rate Calculator Online Free
Target Heart Rate Calculator
Heart Rate Calculator
Leave empty for age-based calculation, or enter for Karvonen method
Formula: Haskell & Fox (220 - age)
Training in the right heart rate zone makes your workouts more effective. Too easy and you are not getting a cardiovascular benefit. Too hard and you cannot sustain the effort or recover properly. This calculator shows your maximum heart rate and target zones so you can train with purpose, whether you are building aerobic base or pushing for peak performance.
Heart Rate Training Zones
Training zones are defined as percentages of your maximum heart rate (MHR). Different zones produce different physiological adaptations. Zone 2 (aerobic base) is where most of your training volume should occur. Zones 4-5 are used for high-intensity intervals and race-pace efforts.
| Zone | % of MHR | Benefit |
|---|---|---|
| Zone 1 (Recovery) | 50-60% | Active recovery, warm-up |
| Zone 2 (Aerobic) | 60-70% | Fat burning, aerobic base |
| Zone 3 (Tempo) | 70-80% | Aerobic efficiency |
| Zone 4 (Threshold) | 80-90% | Lactate threshold, speed |
| Zone 5 (Max) | 90-100% | VO2max, peak power |
Calculating Maximum Heart Rate
The classic formula 220 - Age is a rough estimate with significant individual variation. The Tanaka formula (208 - 0.7 × Age) is slightly more accurate for older adults. The only precise way to know your true max is through a maximal effort test. If you use medication like beta-blockers, your heart rate response is suppressed and these formulas do not apply.
Standard formula: MHR = 220 - Age Tanaka formula: MHR = 208 - (0.7 × Age)
Individual MHR can vary by 10-20 beats from the formula estimate.
Frequently Asked Questions
Is it safe to train at 90% of max heart rate?⌄
For healthy adults cleared for vigorous exercise, brief intervals at 90%+ MHR are safe and effective. However, high-intensity work should make up only a small portion of total training volume (10-20%). If you have heart disease, hypertension, or other conditions, consult your doctor before high-intensity training.
Why does my heart rate vary so much during exercise?⌄
Heart rate responds to temperature, hydration, stress, sleep, caffeine, altitude, and fitness level, not just exercise intensity. On a hot day or after poor sleep, your heart rate will be higher for the same pace. Over-reliance on heart rate without context can be misleading. Use perceived exertion alongside heart rate for better training decisions.
What is heart rate reserve (HRR)?⌄
HRR is your max heart rate minus your resting heart rate. The Karvonen formula uses HRR to set more personalized training zones: Target HR = Resting HR + (% intensity × HRR). This method accounts for fitness level and gives different zone boundaries than simple percentage of MHR.
Does resting heart rate indicate fitness?⌄
A lower resting heart rate generally indicates a more efficient cardiovascular system and better aerobic fitness. Elite endurance athletes often have resting heart rates of 40-50 bpm. The average adult is 60-100 bpm. A consistent downward trend in resting heart rate over weeks of training is a good sign of improving fitness.