Heart rate is the easiest window into how hard your body is working. Training zones turn it into a practical tool: a range of beats per minute for easy days, a different range for hard intervals, and a way of knowing when you have crossed from one to the other. There are two widely used ways to define the zones. One is the American College of Sports Medicine’s classification of exercise intensity, which is the basis of health guidelines. The other is the five-zone scheme popular with coaches and watches, which splits the range from 50 to 100 percent of maximum heart rate into ten-point bands. This calculator gives both, in beats per minute.
How to use the heart rate zone calculator
- Enter your age and choose a maximum heart rate formula.
- Add your resting heart rate (optional) to see zones based on heart rate reserve. Measure it for a full minute on waking.
- Read the ACSM bands for light, moderate, vigorous and near-maximal exercise.
- Read the five training zones if you follow a zone-based plan.
Heart rate zone formulas
%HRmax zone = max × percentage
Heart rate reserve (HRR) = max − resting
Karvonen zone = resting + HRR × percentage
| Intensity (ACSM) | % of max heart rate | % of heart rate reserve |
|---|---|---|
| Very light | below 57 | below 30 |
| Light | 57 – 63 | 30 – 39 |
| Moderate | 64 – 76 | 40 – 59 |
| Vigorous | 77 – 95 | 60 – 89 |
| Near-maximal to maximal | 96 and above | 90 and above |
The classification is from ACSM’s Guidelines for Exercise Testing and Prescription (11th edition, 2021). Maximum heart rate equations are from Fox et al. (1971) and Tanaka et al. (J Am Coll Cardiol 2001;37:153–156). The heart rate reserve method is from Karvonen et al. (1957).
Worked example
A 40-year-old with a resting heart rate of 60 bpm, using 220 − age.
- Maximum = 180 bpm; heart rate reserve = 180 − 60 = 120.
- Moderate by %HRmax: 0.64 × 180 to 0.76 × 180 = 115 – 137 bpm.
- Moderate by reserve: 60 + 0.40 × 120 to 60 + 0.59 × 120 = 108 – 131 bpm.
- Vigorous by %HRmax: 139 – 171 bpm; by reserve: 132 – 167 bpm.
- Five-zone scheme: zone 2 (60–70%) = 108 – 126 bpm; zone 4 (80–90%) = 144 – 162 bpm.
Zones by age
| Age | Max HR (220 − age) | ACSM moderate (64–76%) | ACSM vigorous (77–95%) | Zone 2 (60–70%) | Zone 4 (80–90%) |
|---|---|---|---|---|---|
| 20 | 200 | 128 – 152 bpm | 154 – 190 bpm | 120 – 140 bpm | 160 – 180 bpm |
| 30 | 190 | 122 – 144 bpm | 146 – 181 bpm | 114 – 133 bpm | 152 – 171 bpm |
| 40 | 180 | 115 – 137 bpm | 139 – 171 bpm | 108 – 126 bpm | 144 – 162 bpm |
| 50 | 170 | 109 – 129 bpm | 131 – 162 bpm | 102 – 119 bpm | 136 – 153 bpm |
| 60 | 160 | 102 – 122 bpm | 123 – 152 bpm | 96 – 112 bpm | 128 – 144 bpm |
| 70 | 150 | 96 – 114 bpm | 116 – 143 bpm | 90 – 105 bpm | 120 – 135 bpm |
What each zone is for
- Zone 1, very easy (50–60%). Warm-up, cool-down and recovery days.
- Zone 2, easy aerobic (60–70%). Long steady sessions where you can hold a conversation; see the Zone 2 Heart Rate Calculator.
- Zone 3, moderate (70–80%). Tempo-style work, breathing is heavier but controlled.
- Zone 4, hard (80–90%). Threshold efforts and intervals of several minutes.
- Zone 5, maximal (90–100%). Short, very hard efforts; only brief periods are possible.
Cautions
Maximum heart rate formulas are averages with about 10 beats of scatter, so use zones as a guide and check them against effort: the talk test is a good check. Heat, caffeine, poor sleep and illness raise heart rate at a given effort, and medicines such as beta blockers lower it. See the Max Heart Rate Calculator to compare formulas, the Target Heart Rate Calculator for AHA percentages and the VO2 Max Calculator for aerobic fitness.
This page is for information only and is not medical advice. If you have a heart condition, take medicines that affect heart rate, or are new to exercise, check with a doctor before starting a training plan.
Sources
- American College of Sports Medicine. ACSM’s Guidelines for Exercise Testing and Prescription, 11th edition, 2021.
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol 2001;37:153–156.
- Fox SM, Naughton JP, Haskell WL. Ann Clin Res 1971;3:404–432.
- Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate. Ann Med Exp Biol Fenn 1957;35:307–315.
Frequently asked questions
What are the heart rate zones?
Heart rate zones divide your range of intensities into bands, usually as percentages of maximum heart rate. A common scheme has five zones from very light (zone 1) to maximal (zone 5). The American College of Sports Medicine uses its own classification: light, moderate, vigorous and near-maximal.
Which zone should I train in?
For general health, 150 minutes a week of moderate activity (ACSM moderate, roughly zones 2 and 3) is the usual recommendation. Endurance training mixes easy zone 2 sessions with some harder work in zones 4 and 5. Beginners should start with low and moderate zones and build gradually.
What is the difference between %HRmax and heart rate reserve?
The %HRmax method applies a percentage to your maximum heart rate. The heart rate reserve (Karvonen) method applies it to the gap between maximum and resting heart rate and adds the resting rate back, which personalises zones for your fitness. Enter a resting heart rate to see both.
Are the five zones an official standard?
No. The 10 percent bands are a convention used by many watches and coaching books. The ACSM bands are the sourced reference for health guidance; the calculator shows both so you can see where they overlap.
Do these zones work with heart medication?
Beta blockers and some other medicines lower your heart rate and break the formulas. If you take them, ask your doctor for personal targets and use perceived effort or the talk test instead.