Heart Rate Zone Calculator

Calculate your five training heart rate zones based on your max heart rate.

Heart rate zones are estimates and do not replace medical or professional fitness advice.

Training zonesMax HR or Karvonen methodReviewed for accuracy

Heart rate zone calculator

Enter age, resting heart rate, and optional measured maximum heart rate.

Calculation method
Maximum heart rate formulas are estimates.
Resting heart rate improves heart-rate-reserve zone estimates.
Use measured max heart rate only if it was tested safely.

Estimated maximum heart rate

190

bpm

Based on 220 − age using the Karvonen method.

Zone 2 range

138–151 bpm

Easy aerobic training range.

Heart rate reserve

130 bpm

Max HR minus resting heart rate.

Threshold zone

164–177 bpm

Higher-intensity training range.

Uses standard heart rate zone formulas. Reviewed for accuracy. Estimate only. Does not replace medical or professional fitness advice.

Personalized interpretation

Your estimated maximum heart rate is 190 bpm.

Your Zone 2 range is approximately 138–151 bpm using the selected method.

Lower zones are commonly used for easy aerobic training and recovery. Higher zones can be more demanding and may not be appropriate for everyone.

If you have heart symptoms, medical conditions, or are new to exercise, consider professional guidance before high-intensity training.

Heart rate zone chart

Zone 1

Very light / recovery

Warm-up, cool-down, easy recovery

50–60%

125–138 bpm

Zone 2

Easy aerobic

Base endurance and comfortable aerobic work

60–70%

138–151 bpm

Zone 3

Moderate / tempo

Steady moderate workouts

70–80%

151–164 bpm

Zone 4

Hard / threshold

Threshold intervals and demanding efforts

80–90%

164–177 bpm

Zone 5

Very hard / near max

Short high-intensity efforts

90–100%

177–190 bpm

What heart rate zones mean

Heart rate zones divide exercise intensity into ranges.
Zones are based on maximum heart rate or heart rate reserve.
Lower zones are easier and more sustainable.
Higher zones are more intense and require more recovery.

Maximum heart rate and resting heart rate

Maximum heart rate is the highest heart rate reached during intense exercise. Formula estimates such as 220 − age are rough estimates.

Resting heart rate is measured at rest. Heart rate reserve equals max HR minus resting HR, and measured values may differ from formula estimates.

Percentage max HR vs Karvonen method

Percentage max HR

Uses only maximum heart rate. It is simple and commonly used.

Karvonen method

Uses heart rate reserve and resting heart rate, which can feel more personalized.

Both methods are estimates and should be adjusted based on response, symptoms, and professional guidance when needed.

How to use zones for training

Zone 1

Very light / recovery

Warm-up, cool-down, easy recovery

Zone 2

Easy aerobic

Base endurance and comfortable aerobic work

Zone 3

Moderate / tempo

Steady moderate workouts

Zone 4

Hard / threshold

Threshold intervals and demanding efforts

Zone 5

Very hard / near max

Short high-intensity efforts

Beginners may benefit from easier zones first. High-intensity training should be approached gradually, and recovery matters.

Accuracy limits and safety notes

Heart rate zone estimates can vary for many reasons. Stop exercising and seek medical attention if you experience chest pain, fainting, severe shortness of breath, unusual dizziness, or concerning symptoms.

Age-based formula error
Fitness level
Medications
Caffeine
Stress
Heat
Dehydration
Sleep
Illness
Wearable sensor accuracy
Individual heart rate response

Formula explanation

Estimated Max Heart Rate = 220 − Age
Heart Rate Reserve = Max Heart Rate − Resting Heart Rate
Percentage Max HR: Target HR = Max HR × Zone Percentage
Karvonen: Target HR = Resting HR + Heart Rate Reserve × Zone Percentage

Example: max HR method

Age 40 → estimated max HR 180 bpm. Zone 2 at 60–70% = 108–126 bpm.

Example: Karvonen

Max HR 180, resting HR 60, reserve 120. Zone 2 = 60 + 120 × 0.60 to 0.70 = 132–144 bpm.

Frequently Asked Questions