Fat Burning Zone Calculator For Weight Loss

Fat Burning Zone Calculator For Weight Loss

Your heart rate is one of the best indicators of how hard your body is working during a workout.

The “Fat-Burning Zone” Is A Point At 60-70% Of Your Max Hr, When Fat Oxidation Is Maximised

During high-intensity exercise (Anaerobic Exercise)  the % of Fat Burned Is Lower because our bodies resort to our carbohydrate reserves. However, due to intense exercise, the total calorie consumption is higher. We burn more calories due to the hard muscle work – even AFTER the run.

BMR Calculator


I’m a big believer in High-Intensity Interval Training (HITT) with fitness running machines, as a very effective way to improve overall cardiovascular fitness. But to lose fat your best bet would be to use Zone 2 Heart Rate Training discussed below.

Fat Burning Zone Calculator

How to Measure Maximum Heart Rate (MHR)

There are many formulas for calculating your maximum heart rate, however, the most studied are the following:

  • Fox formula (most common formula for men and women): 220 – age
  • Gulati formula (women only): 206 – (0.88 × age)2
  • The HUNT formula (men and women who are active): 211 – (0.64 x age)
  • Tanaka formula (men and women over age 40): 208 – (0.7 × age)3

So if you are looking for  cardiovascular fitness or burning more calories in the shortest time-go for High-Intensity Exercises like HITT

High-Intensity Interval Training (HITT)

  • HIIT is one of the most effective ways to lose weight through most Calories lost are NOT from FAT.
  • HITT is an intense aerobic method that includes sprinting or Tabata-styled workouts designed to condition the body in less time than steady-state low-intensity cardio.
  • One HIIT session will leave your metabolism burning and increase in calories for up to 24 hours post-training session.
  • Example of HITT exercise: Try skipping for 20 seconds as fast as possible, followed by 30 seconds at a slower pace.
  • Any form of exercise where you constantly switch up the rate of intensity to spike your heart rate for brief periods will leave your metabolism buzzing all day long.

What is Fat Burning Zone

The fat-burning zone, in particular, is the range of heart-rate intensity in which you burn the most calories from fat. It’s said to take place at around 60-70 % of your Maximum Heart Rate. (MH)

Which part of the body loses fat first?

  • Losing weight is an internal process.
  • You will first lose hard fat that surrounds your organs like the heart, liver, and kidneys and then you will start to lose soft fat like belly, waistline, and thigh fat.
  • The fat loss from around the organs makes you leaner and stronger.

How long should you be in the fat-burning zone?

For fat burning and general body fitness, it’s recommended to do 150 total minutes in zone 2 per week. This will be helpful in your body composition, and will also help with other positive effects such as improved glucose sensitivity and good heart health.

Difference Between Cardio Zone and Fat Burn Zone

  • When you exercise in a Cardio Zone, you will burn more glycogen, or stored carbohydrates as your main energy source, using less fat as energy source   BUT your total caloric burn and after-burn will be much greater.
  • Calories burned are what results in Weight Loss.
  • When Exercising at Fat Burn Zone you have no after-burn however most Calories burned are from the FAT  and not Carbs

What Happens To Body Fat When You Exercise?

  • FIRST 1-30 MINS=>: Your muscles first burn through stored glycogen for energy.
  • 30 MINS + => “After about 30  minutes of aerobic exercise, your body starts burning mainly fat,” says Dr. Burguera. (If you’re exercising moderately, this takes about an hour.)

Facts About Fat Burning Zone ,How To Calculate Fat Burning Zone And Using Fat Burning Zone Heart Rate To Lose Fat

Want To Lose Fat? You Need Zone 2 Exercise

  • In zone 2 heart rate exercise you’ll preferentially use fat for fuel, making this a very effective way to lose body fat;
  • Exercise in zone 2 for 150 minutes per week for body fat loss
  • Zone 2 is not only effective in helping you lose body fat,
  • Great benefits to improving glucose sensitivity
  • Reduce Heart Disease Risk.
  • Fuel  used by the muscles during this type of training is from FAT
  • So if you want to lose fat you’ll want to exercise in zone 2 because fat is used for fuel.
  • Zone 2 training is also known to improve metabolic syndrome, type 2 diabetes, and reduce heart disease risk.

There’s a lot to like about the zone 2 exercises.

Exercise Training Zones

Heart Rate Chart by Training Intensity

AgeLow Intensity
Moderate Intensity

Vigorous Intensity

20 97-116116-135135-155145-164194
25 95-114114-134133-152143-162190
30 93-112112-131131-149140-159187
35 92-110110-128128-147138-156183
40 90-108108-126126-144135-153180
45 88-106106-124124-141133-150177
50 87-104104-121121-139130-147173
55 95-102102-119119-136128-145170
60 83-100100-117117-133125-142167
65 82-9898-114114-131123-139163
70 80-9696-112112-128120-136160
75 78-9494-110110-125117-133157
80 77-9292-107107-123115-130153
  • Exercise physiologists divide efforts into 5 or 6 “zones” depending on metrics such as blood lactate or heart rate.
  • For heart rate zones you’ll commonly see 5 zones based on a percentage of maximum heart rate.

Five Heart Rate Zones

There are five different heart rate zones (1–5) and your training plan can (and should) include workouts in all five zones. This HR zones chart shows the level of intensity and percentage of Maximum Heart Rate used in each one.

ZoneIntensityPercentage of HRmax
Zone 1Very light50–60%
Zone 2Light60–70%
Zone 3Moderate70–80%
Zone 4Hard80–90%
Zone 5Maximum90–100%

Below is a breakdown of what each heart rate zone means and what the benefits of training in that heart rate zone are.

  • Zone 2 is generally recognized as 60% to 70% of HR max,
  • zone 3 from 70% to 80%,
  • From 4 zone 80% to 90%, and
  • zone 5 from 90% to 100%.

Eat well and exercise in a 50-80% maximum pulse zone.

I recently came across Peter Attia’s podcast featuring Inigo San Millan of UC Boulder where a Valid Explanation was provided why zone 2 is the most effective for fat burning.

In zone 2, slow-twitch type 1 muscle fibers are activated, and these fibers use fat for power.

Fat Burning Zone Calculator For Weight Loss
Fat Burning Zone Calculator

How To Know When You’re In Zone 2 Exercise

  1. Physiology laboratory testing.

  • Most accurate but also the most involved method.
  • While either running or cycling in a highly controlled environment you’ll have some combination of blood lactate testing, and also a measurement of Functional Threshold Power (cycling) or Threshold Running Pace.
  • If you’re an elite endurance athlete this is the best way to go.

2. Heart Rate Zone Estimation With Chest Strap Or Wrist-Worn Heart Rate Monitor.

  • Devices made by Polar, Garmin, Apple, and others can estimate your maximum heart rate and then calculate when you’re in the 60% to 70% range roughly corresponding to zone 2. (I use a Garmin Fenix 5S and find this to be a great way to know when I’m in various training zones with an easily readable display on the watch. Highly recommended for the serious amateur.)

    3. Count Your Pulse With A Standard Watch.

  • For moderate-intensity physical activity, your target heart rate should be between 64% and 76% of your maximum heart rate. You can estimate your maximum heart rate based on your age.
  • To estimate your maximum age-related heart rate, subtract your age from 220.
  • For example, for a 50-year-old person, the estimated maximum age-related heart rate would be calculated as
  • 220 – 50 years = 170 beats per minute (bpm).
  • For Zone 2 : The 64% and 76% levels would be:

64% level: 170 x 0.64 = 109 bpm, and
76% level: 170 x 0.76 = 129 bpm

  • This shows that moderate-intensity physical activity for a 50-year-old person will require that the heart rate remains between 109 and 129 bpm during physical activity.
  1. First, get an estimate of your maximum heart rate with this formula: 220 – age.
  2. From the maximum, multiply by 0.6 for the low end of zone 2 and multiply by 0.7 for your upper end.
  3. After about 10 minutes of exercise stop, count your pulse for 15 seconds, and multiply by 4 for your heart rate.
  4. Adjust your exercise intensity to stay in zone 2.

4. Use your personal estimate of exertion and a “talk test”.

  • On a zero to 10 scale make an estimate of how hard you’re exercising, with “10” being the most intense thing you can imagine. In zone 2 you want to be about 5 or 6.
  • You should be able to talk and hold a conversation but not necessarily to sing a song.
  • That’s the talk test.
  • This will do if you don’t have another option.

Further Heart Rate Zone Tips

  • Once you have your own set of zones, you can start to differentiate between your training intensities. As a general rule of thumb, for endurance sports such as running, cycling and triathlon you should aim to do 80% of your training in Zones 1 to 2 (mainly Zone 2). And the remaining 20% of your training in Zones 3 to 5.
  • Note that your heart rate zones may differ between sports, such as cycling and running. For example, cycling heart rate zones are commonly 5-8 beats lower than running heart rate zones. If you do both sports, you may need to create two different sets of zones, based on your max heart rate in each one. Or create yourself a set of running zones, and then subtract 5 to 8 heartbeats off each zone, as an estimate of your cycling zones.
  • Your heart rate is a reflection of how hard your body is working, in a given moment. Heart rate monitoring is most useful during steady-state workouts, in which you mostly train at one intensity throughout.
  • Heart rate monitoring is less useful during workouts that involve short, sharp efforts. This is because your heart rate may take minutes to fully reflect changes in your intensity. For example, you could run at a steady-state fast pace for 30-seconds, where your heart rate would be continually climbing throughout. Therefore, during short, hard efforts, it’s good to include other measures like pace, power output, or Rate of Perceived Exertion to help gauge your intensity.


If you have an injury, illness, or take certain medications, it’s smart to consult your doctor. For example, beta-blockers, common medications for blood pressure, can interfere with the heart’s natural response. Whether you’re exercising for health, fitness, or weight loss, to get the best results it’s smart to vary your workouts in each of the heart rate zones.

When in doubt, seek advice from a nutritionist and exercise under a watchful eye of a Personal Trainer. The solution is – to take less and spend more calories. And enjoy finding your zone! Hope you like our Fat Burning Zone Calculator post.



Here are the sources of the Fat Burning Zone Calculator:

  1. Deborah Riebe, Jonathan K Ehrman, Gary Liguori, Meir Magal. Chapter 6 General Principles of Exercise Prescription. In: ACSM’s Guidelines for Exercise Testing and Prescription. 10th Ed. Wolters Kluwer/Lippincott Williams & Wilkins, Philadelphia, PA: 2018, 143-179.
  2. Physical Activity Guidelines Advisory Committee pdf icon external icon [PDF-4.6MB]. Physical Activity Guidelines Advisory Committee Report, 2008. Washington, DC: U.S. Dept of Health and Human Services; 2008.

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