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Heart Rate Zones Calculator

Quickly calculate your heart rate training zones using your maximum heart rate or heart rate reserve and get personalized training sessions based on these zones.

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Heart Rate Zones


This calculator allows you to quickly calculate target heart rate zones, which can be used to help runners, cyclists, and other athletes train more effectively, whether the goal is to improve performance, burn fat, increase speed, or to achieve a better balance of training.

What is a heart rate zone?

A heart rate zone is simply a range of heart rates (measured in beats per minute, or bpm) that specifies the intensity of exercise required to achieve a particular training effect.

Zones are identified for various outcomes, such as burning fat, improving lactate threshold or VO2 max, or building endurance.

Heart Rate Zone Training Benefits

Why heart rate zone training is useful

Being aware of your personal heart rate training zones and understanding them will help ensure you're getting the most from your workouts and balancing your schedule well. If you have a specific need, then you can prioritise training within the appropriate zone.

When heart rate zone training is useful

Heart rate zone training is particularly useful when pace is not a good indicator of effort. This could be because you're running or cycling on a hilly course, in adverse weather conditions, on rough terrain, or because you're fatigued. Whereas your pace may vary significantly according to these factors, your heart rate will fluctuate far less, and so is a more suitable measure of how hard you're working.

The Zones

We identify five main zones that are set according to either a percentage of maximum heart rate or a percentage of heart rate reserve. Running or cycling at any heart rate within a zone will, broadly speaking, have a training effect that is similar to exercising at other heart rates within the same zone.

In addition, we've included two fat burning zones: one for men and one for women, since optimal fat burning tends to take place at different intensities for males and females.

Heart rate zones ranges and descriptions

The table below shows target heart rate zones and the ranges of percentages of maximum heart rate (MHR) and heart rate reserve (HRR) that correspond to each zone.

  MHR Range HRR Range Description
Zone 1/Light
< 68% < 60%
Zone 1/Light
< 68% MHR
< 60% HRR
This zone includes very light exercise, usually reserved for early on in a warm up or for short recovery runs. Some coaches consider exercise at this intensity to constitute "junk miles".
Zone 2/Aerobic
68-81% 60-75%
Zone 2/Aerobic
68-81% MHR
60-75% HRR
The bulk of training should take place in this zone. This zone is good for general aerobic conditioning and improving endurance. Zone 2 is sometimes called the "fat burning" zone since it's often believed you will burn fat most efficiently when running within this range of intensities, but it's more useful to include separate zones for fat burning. This zone is also good for longer runs, warm ups and cool downs.
Zone 3/High aerobic
82-86% 76-83%
Zone 3/High aerobic
82-86% MHR
76-83% HRR
Training within this zone will improve and strengthen the cardiovascular and peripheral systems, promote increased vascularisation (meaning a greater blood and oxygen supply to muscles), and build resistance to injury. This zone is also a great alternative to zone 2 when you're feeling particularly good.
Zone 4/Anaerobic
87-93% 84-91%
Zone 4/Anaerobic
87-93% MHR
84-91% HRR
This zone covers intensities from just below to just above your anaerobic threshold (the middle of this zone is roughly the intensity you could maintain for an hour in a race situation). Training in this zone can help raise your anaerobic threshold meaning you can run harder and faster at both this and other intensities.
Zone 5/Red Line
94-100% 92-100%
Zone 5/Red Line
94-100% MHR
92-100% HRR
This is the zone that is used for interval training. Training in this zone will help train your fast twitch muscle fibres and raise your VO2 Max. This type of training should be limited.
Fat Burning Zone - Men
58-74% 50-70%
Fat Burning Zone - Men
58-74% MHR
50-70% HRR
This is the heart rate range for men within which calorie burn from fat will be optimized. Note that the optimal range for men is slightly lower than that for women.
Fat Burning Zone - Women
60-79% 52-74%
Fat Burning Zone - Women
60-79% MHR
52-74% HRR
This is the heart rate range for women within which calorie burn from fat will be optimized. Note that the optimal range for women is slightly higher than that for men.

Fat Burning Zones

Much has been made of exercising in heart rate zone 2, often called the "fat-burning zone", since it is commonly believed that you burn fat most efficiently when training in this zone.

However, research has shown that the optimal range of hearts rates for preferentially burning fat takes place at lower heart rates.

Additionally, the fat burn range differs for men and women. For this reason, we've included two additional "fat burning" zones that show these ranges.

This means that if your goal is weight loss then this tool can also be used as a fat burning calculator, or as a zone 2 calculator (although that would now seem to be poorly-named).

Within these zones men will burn an approximate average of 10 Calories per minute of exercise, of which roughly 4 will be from fat stores; women will burn an approximate average of 7.5 Calories per minute of exercise, of which roughly 2.5 will be from fat reserves.

An approach that includes lots of exercise within this zone may be appealing for those who are running or cycling for weight loss. But it's worth noting that although the proportion of fat burned while training in the fat burning zone is greater than at higher heart rates, these greater intensities will bring about an overall greater calorie burn.

For example, running at 68% of maximum heart rate burns roughly 9.2 Calories per minutes, 3.1 of which will be from fat. So, that's about a third of overall calorie burn.

Compare this to running at 87% of maximum heart rate. This intensity burns a greater 14.2 Calories per minute, but only 1.7 of those Calories will be from fat. So, that's about 12 percent of overall calorie burn.

Also worthy of consideration is the fact that it's possible to spend longer training at lower intensities and this type of exercise will typically require less recovery.

The best approach is probably similar to that of those who are training for performance rather than calorie or fat burn, and to do most of your training in the lower zones, but also to include training sessions that hit the higher zones since they can bring about various other benefits, both in terms of training effect and body composition changes.

Just to confuse matters, there is also evidence that High Intensity Intermittent Exercise (HIIE) may be better than other types of exercise for fat reduction.

Junk miles

Running or biking in zone 1 takes place at below 68% MHR or 60% HRR. Some running coaches would argue that miles run at such low intensities fall into the category of "junk miles". I.e. those miles which are run at a pace too slow to elicit benefits.

Debates about junk miles have raged for a long time, and despite the extreme view of some coaches, training at low aerobic intensities can still bring about improvements in fitness. It depends on a variety of factors. For example, running at 60% MHR or 55% HRR is better than doing nothing. On the other hand, doing all your mileage at this intensity is unlikely to bring about the same improvements as a good mix of training that includes the other zones.

We suggest that this zone 1 can be a useful alternative to zone 2 if you feel like taking things a little easier. Conversely, if you're feeling especially good, then zone 3 can be a good alternative to zone 2.

Using your personal zones

The zone margins have been chosen carefully to closely reflect the correct training, or fat burning, zones for a majority of runners.

But bear in mind that your personal heart rate zones are very likely to be a little different from what is listed here. However, since there is overlap in the training effects for each zone, and there is also a wide range to play with, this shouldn't cause too many problems. Try to see the zones as guides rather than targets. If you're concerned about hitting the correct intensities then you can concentrate on doing most of your running in the middle of any particular zone. What is probably most beneficial in practise is to run at a wide range of intensities within and across the different zones.

If you plan to make use of heart rate zones then it's really important you have a good idea of your true maximum heart rate. Maximum heart rate calculators can be useful for getting an idea, but individuals will vary wildly, even at different ages, so we strongly recommend performing a proper maximum heart rate test as detailed in our heart rate training guide. Our guide also gives advice on how to determine your resting heart rate.

Many GPS watches and heart rate monitors, such as those offered by Garmin and Polar, include a facility that allows you to set your personal heart rate zones and to then monitor your zone during training.

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How Heart Rate Zones Are Calculated

The calculator offers two ways to calculate your personalized heart rate training zones. You can use either your maximum heart rate, or your heart rate reserve.

Maximum Heart Rate

The first way of calculating heart rate zones is to simply use your maximum heart rate.

For example, the upper and lower zone 2 heart rates, which range from 68% to 81% of max HR, can be calculated as follows:

Lower heart rate value = Max HR x 0.68

Upper heart rate value = Max HR x 0.81

You can estimate your maximum heart rate using our calculator, or you can carry out a maximum heart rate test, which is far more reliable.

Heart Rate Reserve

The second option on our heart rate zone calculator uses the heart rate resever method, or Karvonen method, to determine the zones. The heart rate reserve method is likely to provide slightly more accurate results.

Heart Rate Reserve (HRR) is calculated by subtracting your resting heart rate from your maximum heart rate.

Heart rate reserve is a key element of the Karvonen formula. The Karvonen formula is as follows:

HRR% = (HRtrain - HRrest) / (HRmax - HRrest)

Where HRR% is a percentage of heart rate reserve, HRmax is maximum heart rate, HRrest is resting heart rate, and HRtrain is a particular training heart rate

This allows us to calculate a percentage of a person's heart rate reserve based on their maximum and resting heart rates, and their heart rate during exercise.

However, for our purposes, we wish to know a heart rate during exercise (i.e. a target heart rate for our zones). So we can rearrange:

HRtrain = (HRmax - HRrest) x HRR% + HRrest

Heart rate reserve is sometimes known as working heart rate. See our article on training by heart rate for details of how to calculate your resting and maximum heart rates.

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