Heart Rate Zone Calculator: 5 Training Zones by Age and Resting HR
Enter your age and resting heart rate to get your five heart rate training zones in beats per minute, calculated with either the simple percentage method or the personalized Karvonen formula. Choose whether to use the age-predicted maximum heart rate or enter a measured value from a field test. The show-your-work panel walks through every step of the math, and the zone table shows the exact bpm range and training purpose for each zone.
Formula
Worked example
A 30-year-old with a resting HR of 60 bpm. Estimated max HR = 220 - 30 = 190 bpm. Heart rate reserve = 190 - 60 = 130 bpm. Karvonen Zone 2 (60-70%): lower = (130 x 0.60) + 60 = 138 bpm, upper = (130 x 0.70) + 60 = 151 bpm. Simple Zone 2: lower = 190 x 0.60 = 114 bpm, upper = 190 x 0.70 = 133 bpm. The Karvonen result is higher because it anchors zones above the resting rate.
What are heart rate zones?
Heart rate zones are ranges of beats per minute that correspond to different exercise intensities. Training science typically divides effort into five zones, from easy recovery work at Zone 1 up to all-out maximum effort at Zone 5. Each zone stresses different energy systems and produces different physiological adaptations. Zone 2 builds the aerobic base and trains the body to burn fat efficiently. Zone 4 pushes the lactate threshold upward, the speed at which lactic acid starts to accumulate faster than the body can clear it. Zone 5 develops VO2 max, the upper ceiling of oxygen uptake. A well-designed training plan distributes time across zones with purpose: most coaches recommend spending the majority of volume in Zones 1 and 2, with targeted threshold and intensity sessions in Zones 4 and 5.
Karvonen method vs. simple percentage method
The simple percentage method sets zones as percentages of your maximum heart rate. It is quick and requires only an age estimate, but it ignores individual variation in resting heart rate. The Karvonen method uses heart rate reserve (max HR minus resting HR) instead. Because it anchors zones above your resting rate, the resulting bpm targets are higher for people with a lower resting heart rate, reflecting their greater cardiovascular efficiency. For example, a runner with a max HR of 190 bpm and a resting HR of 45 bpm has a reserve of 145 bpm. Karvonen Zone 2 at 60-70% starts at 132 bpm, compared to 114 bpm with the simple method. The Karvonen result is generally considered more accurate for trained athletes. For beginners or those who do not know their resting HR precisely, the simple method provides a reasonable starting point.
How to find your maximum heart rate
The default formula (220 minus age) is convenient but imprecise: the standard deviation is around 10-12 beats per minute, meaning your true max could easily be 10 bpm higher or lower than the formula predicts. The Tanaka formula (208 minus 0.7 times age) has a smaller error for adults over 40 and is the better choice for older athletes. A measured max HR from a field or laboratory test is always more accurate than either formula.
- 3-km time trial: After a full warm-up, run 3 km at increasing effort, all-out in the final 400 m. Record the peak reading on your heart rate monitor.
- Hill repeat test: After a warm-up, sprint uphill for 2-3 minutes at maximal effort. Repeat three times. The highest reading is close to your true max.
- Lab VO2 max test: The most accurate option, conducted on a treadmill or ergometer with medical supervision.
Once you have a measured value, enter it in the "I know my measured max HR" option for the most accurate zones.
How to train in each zone and why it matters
Zone allocation shapes fitness gains. Research consistently shows that polarized or 80/20 training (about 80% of sessions in Zones 1-2, 20% in Zones 4-5, minimal time in Zone 3) produces better endurance results than training centered in Zone 3, which is often called the "gray zone" because it is hard enough to cause fatigue but not intense enough to drive strong physiological adaptations.
- Zone 1-2: Long slow runs, easy cycling, recovery walks. Can be sustained for hours. Builds mitochondrial density and fat-burning efficiency.
- Zone 3: Tempo runs, steady-state cycling. Useful in moderation, but easy to overdo. Leaves you tired for quality sessions without maximizing either aerobic or threshold gains.
- Zone 4: Threshold intervals (e.g., 4 x 8 minutes). Raises your lactate threshold, the key determinant of performance in events lasting 20-60 minutes.
- Zone 5: Short, maximal efforts (e.g., 6 x 30 seconds). Improves VO2 max and neuromuscular power. Use sparingly and allow full recovery between sessions.
Limitations and when to see a doctor
Heart rate zones are guidelines, not absolutes. Factors that reduce their accuracy include heat and humidity (heart rate rises for a given pace in the heat), caffeine, dehydration, altitude, illness, and overtraining (cardiac drift can inflate HR by 10-15 bpm late in a long session). Some medications, particularly beta-blockers, artificially suppress maximum heart rate and make standard formulas useless; anyone on cardiac medication should have a physician guide their exercise intensity using perceived exertion rather than heart rate. The formulas here apply to adults in general good health. If you experience chest pain, dizziness, or unusual shortness of breath during exercise, stop and seek medical advice. This calculator is an educational tool and is not a substitute for individualized advice from a qualified sports medicine practitioner.
Standard 5-zone heart rate training system
| Zone | Name | Intensity | Key benefit | Effort feel |
|---|---|---|---|---|
| Zone 1 | Recovery | 50-60% | Active recovery, beginners | Very easy - can hold a full conversation |
| Zone 2 | Endurance | 60-70% | Fat burning, aerobic base | Easy - can speak in sentences |
| Zone 3 | Aerobic | 70-80% | Cardiovascular fitness | Moderate - can speak a few words |
| Zone 4 | Threshold | 80-90% | Lactate threshold, race fitness | Hard - breathing is labored |
| Zone 5 | Max effort | 90-100% | VO2 max, speed and power | Very hard - cannot speak |
Intensity percentages apply to heart rate reserve (Karvonen) or maximum heart rate (simple method).
Frequently asked questions
What is Zone 2 heart rate training?
Zone 2 is a low-to-moderate intensity band, typically 60-70% of max HR or heart rate reserve, where you can hold a conversation but are clearly working. It is considered the primary zone for building aerobic base and improving the body's ability to use fat as fuel. Most endurance coaches recommend spending 70-80% of total weekly training time in Zone 2.
Which is better: the Karvonen method or the simple percentage method?
The Karvonen method is generally more accurate for individuals because it accounts for your personal resting heart rate through the heart rate reserve calculation. A fit athlete with a low resting HR will have higher zone targets than someone of the same age with a high resting HR. The simple method ignores this difference, so it tends to underestimate zone intensity for fit individuals and overestimate it for sedentary ones.
How do I measure my resting heart rate?
Measure your resting heart rate first thing in the morning before getting out of bed. Count your pulse at your wrist or neck for 60 seconds, or use a heart rate monitor. Take readings on three consecutive mornings and average them for best accuracy. A typical adult resting HR is 60-80 bpm; trained endurance athletes often measure below 50 bpm.
Is the 220 minus age formula accurate?
It is a useful approximation but not highly accurate for individuals. The standard deviation around the formula is about 10-12 bpm, so your true maximum could easily differ from the prediction by that amount. The Tanaka formula (208 minus 0.7 times age) is somewhat more accurate for adults over 40. For serious training, a field test or laboratory VO2 max test gives a measured value that removes this uncertainty.
Why is my Zone 5 so narrow?
Zone 5 covers 90-100% of max HR or HRR, which is only a 10 percentage-point band. In absolute bpm terms this is usually 15-20 beats. The zone is intentionally narrow because truly maximal effort is only sustainable for a few seconds to two minutes, and training at this intensity is used sparingly. Most athletes spend fewer than 5% of their weekly training time in Zone 5.
Can I use these zones for cycling, rowing, or swimming?
Yes, the same percentage-based zones apply to any aerobic sport. Note that maximum heart rate tends to be modality-specific: your running max is often 5-10 bpm higher than your cycling max, and swimming max is lower still because of the horizontal position and water cooling effect. For best results, determine your max HR in the specific activity you are training for.
What if I am on beta-blockers or heart medication?
Beta-blockers and several other cardiac medications suppress heart rate, making standard formulas and percentage-based zones unreliable. Do not use heart rate zones calculated here as an exercise guide if you are on these medications. Your physician or cardiologist can advise on appropriate exercise intensity, often using perceived exertion scales such as the Borg RPE scale instead of heart rate.
Sources
- Karvonen M et al., "The effects of training on heart rate", Annals of Medicine and Experimental Biology (1957)
- Tanaka H et al., "Age-predicted maximal heart rate revisited", Journal of the American College of Cardiology (2001)
- Seiler S, "What is best practice for training intensity and duration distribution in endurance athletes?", International Journal of Sports Physiology and Performance (2010)