What is Heart Rate?

Your heart rate is the number of times your heart beats in one minute. It’s measured in beats per minute (bpm).

To get the most out of the target heart rate calculator, it helps to understand a few key terms:

• Resting heart rate (RHR)
• Maximum heart rate (MHR)
• Heart rate reserve (HRR)

Maximum Heart Rate (MHR)

Your maximum heart rate is the highest number of beats your heart can reach during hard exercise.

The most accurate way to find it is by doing a medical stress test on a treadmill with heart monitoring. But most people use formulas to estimate it, like:

• 220 – age (Haskell & Fox, 1971)
• 208 – 0.7 × age (Tanaka, Monahan & Seals, 2001)
• 211 – 0.64 × age (Nes et al., 2013)

These formulas give an average estimate based on age. But everyone’s heart is different. For example, Olympic athletes in their 20s had max heart rates ranging from 160 to 220 bpm!

Resting Heart Rate (RHR)

Your resting heart rate is how fast your heart beats when you’re calm, relaxed, and not exercising.

You can check it by counting your pulse for one full minute.

A normal resting heart rate typically ranges from 50 to 90 beats per minute (bpm).

• If it’s over 100, it may be called tachycardia (too fast).
• If it’s under 50, it may be called bradycardia (too slow)—but this is normal for very fit people and athletes.

Heart Rate Reserve (HRR)

Your heart rate reserve is the difference between your maximum and resting heart rates:

HRR = MHR – RHR

Example:

If your max heart rate is 180 and your resting heart rate is 68:

HRR = 180 – 68 = 112

Target Heart Rate Zones

Your target heart rate zone is the heart rate range you should aim for during exercise to get the most benefit.

• Exercising too high above this zone can lead to fatigue and injury.
• Too low, and your workout may not be effective.

There are 5 heart rate zones, each offering different benefits, like fat burning, endurance building, or peak performance.

Your ideal zone depends on your fitness goal. The calculator will help you find the right range to train safely and effectively.

Understanding Heart Rate Zones

Your target heart rate zones help guide how hard you should work during exercise. These zones are based on your heart rate as a percentage of your maximum heart rate (MHR).

Here’s a quick overview of each heart rate zone:

Zone 1: 50–60% of MHR

• Light activity
• Good for warm-ups, cool-downs, and recovery days
• Easy pace, comfortable breathing

Zone 2: 60–70% of MHR

• Great for burning fat and improving endurance
• Can be maintained for a long time
• Feels like a steady, comfortable effort

Zone 3: 70–80% of MHR

• Moderate to hard effort
• Builds speed, strength, and aerobic capacity
• Breathing becomes heavier

Zone 4: 80–90% of MHR

• High intensity
• Improves the ability to sustain faster paces
• Used in interval or tempo workouts

Zone 5: 90–100% of MHR

• Maximum effort
• Short bursts only—sprinting or peak intervals
• Helps improve speed and heart efficiency
• Requires more recovery time

Each zone offers different benefits, so the best training plans include a mix of zones to balance progress and recovery.

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How We Measure Exercise Intensity

There are different methods to figure out your target heart rate zones. Our calculator supports several options:

1. Haskell & Fox Method (Simple)

This is one of the most popular formulas and only uses your age

MHR = 220 – age 

Example:

You’re 36 years old:

• Max heart rate = 220 – 36 = 184 bpm
• For moderate effort (70–80%):
  • 184 × 0.70 = 129 bpm
  • 184 × 0.80 = 147 bpm
• Target zone: 129–147 bpm

This method is quick and easy, but it’s a rough estimate and may not be accurate for everyone.

2. Karvonen Method (More Accurate)

This method includes your resting heart rate (RHR) for a more personalized result. It uses heart rate reserve (HRR), which is:

HRR = MHR – RHR

Formula for target heart rate:

Target HR = (HRR × % intensity) + RHR

Example (age 36, RHR 70 bpm):

• Max HR = 220 – 36 = 184
• HRR = 184 – 70 = 114
• 70% zone: (114 × 0.70) + 70 = 150
• 80% zone: (114 × 0.80) + 70 = 161
• Target zone: 150–161 bpm

This is the default method used by the calculator if you enter both age and resting heart rate.

3. Tanaka and Nes Methods (Alternative Formulas)

These formulas also estimate MHR based on age:

• Tanaka: MHR = 208 – 0.7 × age
• Nes: MHR = 211 – 0.64 × age

Once MHR is calculated, you can use the same steps above to find your zones.

Rating of Perceived Exertion (RPE)

Not everyone wants to track heart rate. Another way to measure intensity is by how hard the workout feels. This is called RPE—Rating of Perceived Exertion.

Two Common RPE Scales:

1. Borg Scale (6 to 20):

• 6 = no effort
• 20 = maximum effort
• Multiply the number by 10 to estimate the heart rate.
  • Example: RPE 13 ≈ 130 bpm

2. Borg CR10 Scale (0 to 10):

• 0 = nothing at all
• 10 = absolute maximum effort

Studies show most people can accurately estimate how hard they’re working just by how it feels.

How to Calculate Target Heart Rate Using the RPE Scale

To estimate your Target Heart Rate (THR) using the RPE scale, use the following formula:

Where:

• THR = Target Heart Rate
• RHR = Resting Heart Rate
• MHR = Maximum Heart Rate
• B = RPE scale value

Example:

Let’s say you’re exercising at a “Somewhat hard” intensity, which corresponds to an RPE of 13.

You have a maximum heart rate (MHR) of 190 bpm and a resting heart rate (RHR) of 60 bpm.

Using the formula:

So, your estimated target heart rate would be 125 beats per minute at that level of perceived exertion.

Borg CR10 Scale

The Borg CR10 Scale is a simplified version of the original Borg Rating of Perceived Exertion (RPE) scale, ranging from 0 to 10. A rating of 0 indicates no exertion at all, while 10 reflects the maximum effort an individual has ever experienced. This scale helps individuals gauge the intensity of physical activity based on their perception of effort.

You can estimate your Target Heart Rate (THR) using the Borg CR10 scale with the following formula:

Where:

• THR = Target Heart Rate
• RHR = Resting Heart Rate
• MHR = Maximum Heart Rate
• B = RPE value on the CR10 scale

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Example:

Suppose you’re exercising at a “somewhat difficult” level, which corresponds to an RPE value of 4.

Your maximum heart rate is 190 bpm, and your resting heart rate is 60 bpm.

Now plug the values into the formula: