Heart Rate Zone Calculator

Create five training zones based on your age, resting heart rate, and preferred calculation method.

Measure shortly after waking for best accuracy.

Leave blank to estimate with 208 - 0.7 * age.

Estimated max heart rate

184 bpm

Tanaka (208 - 0.7 * age)

Resting heart rate

58 bpm

Heart rate reserve: 126 bpm

Method

Heart rate reserve (Karvonen)

ZoneIntensity rangeHeart rate rangeNotes
Zone 1 - Recovery50% - 60% HRR121 - 133 bpmEasy aerobic work that supports recovery and fat oxidation.
Zone 2 - Endurance60% - 70% HRR133 - 146 bpmAerobic base building with long steady sessions.
Zone 3 - Tempo70% - 80% HRR146 - 158 bpmComfortably hard tempo work that raises lactate threshold.
Zone 4 - Threshold80% - 90% HRR158 - 171 bpmHard efforts near race pace that boost threshold power.
Zone 5 - VO2 Max90% - 100% HRR171 - 184 bpmHigh intensity intervals that target maximal oxygen uptake.

How to Use This Calculator

1

Measure resting heart rate

Use a wearable or manual pulse count while relaxed.

2

Estimate or test maximum heart rate

Provide lab/field test data or leave blank to use an age-based estimate.

3

Select your method

Heart rate reserve is more individualized; percent of max is quick and simple.

4

Apply zones in training

Align workouts with the suggested zones to match goals and recovery.

Formula

Karvonen (heart rate reserve): Target HR = Rest + (Max - Rest) * Intensity

Percent of Max: Target HR = Max * Intensity

Estimated Max: 208 - 0.7 * Age (Tanaka)

Example

Age 40, resting 55 bpm, estimated max 180 bpm. Zone 3 (70 to 80 percent HRR) gives 143 to 155 bpm using the Karvonen method.

Variables

  • Resting HR: baseline beats per minute
  • Max HR: observed or estimated maximum
  • Intensity: zone percentage (0.5 to 1.0)
  • Target HR: training heart rate

Understanding Heart Rate Zones

Heart rate zones help match intensity with training objectives. Combine HR data with perceived exertion and pace or power metrics for a complete view of load.

Zone highlights

  • Zone 1: Warm-ups, cooldowns, and active recovery.
  • Zone 2: Endurance base building and steady aerobic sessions.
  • Zone 3: Tempo work for marathon pace or sweet spot cycling.
  • Zone 4: Threshold intervals and time trial preparation.
  • Zone 5: High intensity intervals that build VO2 max.

Tips

  • Use consistent conditions (hydration, temperature) when comparing sessions.
  • Chest straps provide higher fidelity than optical wrist sensors during intervals.
  • Update resting heart rate monthly to account for fitness adaptations.

Frequently Asked Questions

Which method should I choose?

Use the Karvonen approach if you know your resting heart rate. Choose percent of max for quick calculations or group classes.

What if my resting heart rate varies?

Take several readings on rested mornings and average them. Illness, stress, and fatigue can temporarily raise resting heart rate.

Do my zones change over time?

Yes. As fitness improves, resting heart rate may drop and heart rate reserve increases. Update inputs periodically.

How do wearables calculate zones?

Many devices use percent of max by default. Some allow customization with heart rate reserve if you provide resting heart rate data.

How do heart rate zones relate to pace or power?

Heart rate reflects internal load and lags behind external metrics. Use heart rate zones alongside pace or power for a balanced training plan.