Heart Rate Calculator

This heart rate calculator helps you determine your target heart rate zones for exercise. It uses the Karvonen formula to personalize your results based on age and resting heart rate, making it useful for anyone looking to optimize their cardio workouts.

S. Siddiqui

Edited by

S. SiddiquiFounder & Editor-in-Chief
Sources:CDCNIHWHOMayo ClinicUpdated May 2026

Disclaimer: This tool is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Results are estimates based on population averages. Always consult a qualified healthcare professional before making health decisions.

Your Details

yrs

Max Heart Rate

190 bpm

Zone 1 — Recovery95–114 bpm
50–60% max HRRecovery & mobility

Very light activity. Warm-up, cool-down, active recovery.

Zone 2 — Fat Burn114–133 bpm
60–70% max HRFat oxidation & base fitness

Light aerobic effort. The fat-burning zone — sustainable for long sessions.

Zone 3 — Aerobic133–152 bpm
70–80% max HRCardiovascular fitness

Moderate cardio. Improves aerobic capacity and endurance.

Zone 4 — Threshold152–171 bpm
80–90% max HRSpeed & performance

Hard effort. Increases speed, raises lactate threshold.

Zone 5 — Max Effort171–190 bpm
90–100% max HRPeak power & VO₂ max

Maximum intensity. Short intervals only — improves peak power.

Training Tip

Most endurance coaches recommend spending ~80% of training in Zone 2 and only ~20% at high intensity. This builds aerobic base while preventing overtraining.

What Is the Heart Rate Calculator?

Your heart rate is the number of times your heart beats per minute (bpm). At rest, a healthy adult heart typically beats between 60 and 100 times per minute, though well-trained athletes can have resting rates considerably lower than this. During exercise, your heart rate increases to meet the greater oxygen demands of your working muscles. The American Heart Association recommends exercising within specific heart rate zones to maximise the cardiovascular benefit of physical activity, which is exactly what this calculator helps you figure out.

Target heart rate zones are expressed as a percentage of your maximum heart rate (MHR). Exercising within the correct zone for your goal, whether that is fat burning, aerobic fitness improvement, or high-intensity cardiovascular training, helps you carry out your workout more effectively. The CDC guidance on measuring exercise intensity explains how heart rate zones relate to perceived exertion and why staying within your target zone matters.

How to Use the Heart Rate Calculator

  1. Enter your age. This is the primary input for estimating your maximum heart rate.
  2. Optionally enter your resting heart rate if you know it, measured first thing in the morning before getting up.
  3. The calculator works out your estimated maximum heart rate and target zones.
  4. Note the bpm ranges for each zone and use them to guide your exercise intensity.
  5. To pick up on how your heart rate relates to your overall fitness, come back to these figures alongside the BMR Calculator to understand your resting energy expenditure.

The Formula: Maximum Heart Rate

The most widely used formula for estimating maximum heart rate is the age-based formula first set out in research by Fox and Haskell. It has since been revised by various researchers, but the original remains the most commonly applied in fitness contexts.

Maximum Heart Rate (MHR) = 220 - age

A more refined formula developed by Tanaka in 2001 is sometimes used and tends to be slightly more accurate for older adults:

MHR = 208 - (0.7 x age)

This calculator uses the Tanaka formula for improved accuracy. From your MHR, target heart rate zones are calculated as follows:

Zone % of MHR Training purpose
Warm-up / Recovery 50 to 60% Very light activity, warm-up, recovery days
Fat burning 60 to 70% Moderate aerobic activity, fat metabolism, endurance base
Aerobic fitness 70 to 80% Cardiovascular fitness improvement, sustained effort
Anaerobic threshold 80 to 90% High intensity, performance improvement, lactate threshold training
Maximum effort 90 to 100% Sprint intervals, very brief maximum-effort bursts

Key Considerations

Age-based MHR formulas are population averages and can vary by as much as 10 to 20 bpm for any given individual. As a result, the zones calculated here are starting points for working out your training intensity, not precise personal limits. If you want a more accurate MHR, a graded exercise test carried out by a fitness professional or sports medicine clinician provides a measured figure rather than an estimated one.

Resting heart rate is a useful additional marker of cardiovascular fitness. As your aerobic fitness improves over time, your resting heart rate tends to come down. A resting rate consistently above 100 bpm, known as tachycardia, warrants a conversation with your GP, as does a rate below 40 bpm in someone who is not a trained endurance athlete. On top of that, certain medications, particularly beta-blockers, artificially lower heart rate and make zone-based training from age-predicted MHR less reliable. If you take medication that affects your heart rate, ask your GP or exercise professional about alternative methods for gauging intensity.

The Karvonen method, which uses resting heart rate alongside MHR to calculate personalised zones, is more accurate than percentage of MHR alone for people whose resting heart rate is known. This calculator incorporates the Karvonen formula when you provide your resting heart rate.

What to Do With Your Result

Use your target heart rate zones to guide your workout intensity. For general cardiovascular health, the American Heart Association recommends at least 150 minutes per week of moderate-intensity activity, which corresponds to the fat-burning zone at 60 to 70 percent of MHR, or 75 minutes per week of vigorous activity at 70 to 85 percent of MHR. A heart rate monitor or fitness tracker makes it straightforward to keep track of which zone you are in during exercise.

Conclusion

The heart rate calculator gives you personalised training zones based on your age and, where available, your resting heart rate. Used consistently, it helps you carry out your cardiovascular workouts at the right intensity for your goals, whether you are looking to improve aerobic fitness, burn fat, or train at a higher intensity for performance. As with all fitness metrics, the zones are guides rather than hard limits, and how you feel during exercise is always a valid additional indicator of effort.

Last reviewed: May 31, 2026
Founder's Real-World Experience
S. Siddiqui

S. Siddiqui

Founder & Editor-in-Chief, YourToolsBase

How I discovered I had been training in the wrong zone for two years

I had been going to the gym for about two years and assumed I was doing cardio properly because I was breathing hard and sweating. When I built this calculator and looked into my actual heart rate zones for the first time, the picture turned out to be quite different. Using the Karvonen formula with a resting heart rate of 58 bpm and a maximum of 186 bpm, my moderate aerobic zone came in at 131 to 149 bpm. My HIIT zone came in at 159 to 177 bpm. I had been spending almost all my sessions somewhere around 145 bpm, which is comfortably in the aerobic zone but nowhere near the intensity needed for the fat-burning and cardiovascular adaptation I had been chasing.

With that in mind, I restructured my training across a four-week block: two sessions per week held at 140 bpm for 40 minutes to build aerobic base, and one session per week with four-minute intervals at 165 to 170 bpm with two-minute recoveries. The American Heart Association target heart rate guidance confirms this kind of zone-based periodisation as an effective approach for cardiovascular development. As a result, my resting heart rate dropped from 58 to 53 bpm over the following six weeks.

What changed things was not training harder overall. It was training at the right intensity at the right time, and the calculator gave me the numbers to do that with purpose rather than guesswork.

RHR dropped 58 to 53 bpm6 weeksHIIT zone: 159 to 177 bpm
Also used alongside: BMR Calculator

Frequently Asked Questions

What is a normal resting heart rate?
For most adults, a resting heart rate between 60 and 100 beats per minute is considered normal. Well-trained endurance athletes often have resting rates below 60, sometimes as low as 40 bpm, because a stronger heart pumps more blood per beat and does not need to beat as often. A resting rate consistently above 100 bpm (tachycardia) is worth discussing with a GP.
How do I measure my resting heart rate?
The most accurate way is to measure it first thing in the morning, before getting out of bed. Place two fingers on the inside of your wrist below the thumb or on the side of your neck, count the beats for 60 seconds, and record the number. Measuring on several consecutive mornings and taking the average gives a more reliable figure than a single reading.
What heart rate zone is best for fat burning?
The fat burning zone is generally considered to be 60 to 70 percent of your maximum heart rate. At this intensity, a higher proportion of calories burned comes from fat rather than carbohydrates. That said, higher-intensity exercise burns more total calories in a given time, which can be more effective for overall fat loss. The best zone depends on your fitness level and how long you can sustain the effort.
Why does maximum heart rate decrease with age?
Maximum heart rate declines with age as a result of changes in the heart's electrical system and a gradual reduction in the maximum rate at which the sinoatrial node fires. This is a normal physiological process and does not reflect poor health. It is why age is the primary variable in MHR estimation formulas.
Can medications affect my target heart rate zones?
Yes. Beta-blockers, which are commonly prescribed for high blood pressure, heart conditions, and anxiety, lower heart rate at rest and during exercise. If you take beta-blockers or other medications that affect heart rate, standard age-based target zones will not be accurate for you. Ask your GP or a cardiac rehabilitation professional about alternative methods for gauging exercise intensity, such as the Rating of Perceived Exertion (RPE) scale.
How often should I exercise in each heart rate zone?
Most fitness programmes recommend spending the majority of training time, around 70 to 80 percent, in the moderate aerobic zone (70 to 80 percent of MHR) and a smaller portion in higher-intensity zones. The American Heart Association's guidance for general cardiovascular health recommends at least 150 minutes per week of moderate activity or 75 minutes of vigorous activity. Consistently training at maximum effort without adequate recovery increases injury risk.

∑ Formula

Rate This Tool

Was this tool helpful?

Be the first to rate this tool

💡 Pro Tip

Zone 2 training (60–70% max HR) is the most efficient for fat burning and aerobic base building. Most people train too hard, too often.

About the Author

S. Siddiqui

S. Siddiqui

Founder & Editor-in-Chief

LinkedIn Profile

S. Siddiqui is the founder and editor-in-chief of YourToolsBase, overseeing all content, tool accuracy, and editorial standards.

View full profile

Authoritative Sources

Formulas and data in this tool are based on guidelines from the above sources.