Heart Rate Zone Calculator

Calculate target training heart rate zones using scientific formulas (Fox, Tanaka, Gellish, Karvonen) to optimize aerobic and anaerobic conditioning.

Clinically Audited
Fox, Tanaka & Gellish Models
Karvonen Reserve Training
Interactive Zones Scale
30 years
1 year120 years
60 BPM
BPM
30 BPM120 BPM
Estimated Max Heart Rate (MHR)
187 BPM
Calculated using the Tanaka formula.
Intensity Scale Map
Resting: 60 BPMMax: 187 BPM
Your Target Heart Rate Zones
Zone 1: Active Recovery
Intensity: 50% - 60%
124 - 136 BPM
Ideal for warm-ups, cool-downs, and active recovery. Builds a cardiovascular base and promotes blood flow without training stress.
Zone 2: Aerobic / Endurance
Intensity: 60% - 70%
136 - 149 BPM
Builds basic aerobic capacity and optimizes fat metabolism. The standard zone for long-distance training and general endurance.
Zone 3: Tempo / Aerobic Power
Intensity: 70% - 80%
149 - 162 BPM
Improves aerobic power and cardiovascular efficiency. Training here is moderately hard and enhances skeletal muscle capillary density.
Zone 4: Anaerobic Threshold
Intensity: 80% - 90%
162 - 174 BPM
Increases lactate tolerance and anaerobic threshold. Improves your ability to maintain high speed and power before fatigue set.
Zone 5: VO2 Max / Redline
Intensity: 90% - 100%
174 - 187 BPM
Maximum effort sprints and explosive power training. Increases maximal aerobic capacity (VO2 max) and peak velocity.
Step-by-Step Substitution
Karvonen Method: HRmax = 208 - 0.7 × age HRR = HRmax - HRrest Target HR = (HRR × Intensity %) + HRrest
HRmax = 208 - (0.7 × 30) = 208 - 21 = 187 BPM HRR = 187 - 60 = 127 BPM Example for Zone 2 (60% to 70%): Min: (127 × 0.60) + 60 = 136.2 BPM Max: (127 × 0.70) + 60 = 148.9 BPM
Scientific References & Assumptions
Assumptions:
  • Zones approximate physiological aerobic and anaerobic thresholds (variance ±5-10% typical).
  • Assumes the user is a healthy adult and not taking heart rate suppressing medications (e.g. beta-blockers).
  • Resting heart rate represents a true baseline resting pulse (taken waking).
Sources & Citations:
  • Tanaka, H., Monahan, K. D., & Seals, D. R. (2001). Age-predicted maximal heart rate revisited. JACC.
  • Gellish, R. L., et al. (2007). Longitudinal modeling of the relationship between age and maximal heart rate. MSSE.
  • Karvonen, M. J., Kentala, E., & Mustala, O. (1957). The effects of training on heart rate: a longitudinal study. Ann Med Exp Biol Fenn.

Frequently Asked Questions

What is a heart rate zone?

A heart rate zone is a range of heartbeats per minute (BPM) that corresponds to a specific exercise intensity, helping you target particular energy pathways (like fat oxidation or lactate clearance).

How do you calculate heart rate zones?

Zones are calculated by finding your maximum heart rate (using formulas like Tanaka or Fox) and dividing it into percentage ranges. The Karvonen method also adjusts for your resting heart rate.

Which heart rate zone formula is the most accurate?

The Tanaka formula (208 - 0.7 * age) is widely considered more accurate than the traditional Fox formula, as it reduces error margins in middle-aged and older populations. For active athletes, Gellish is also highly recommended.

What is the Karvonen formula?

The Karvonen formula calculates target heart rates by incorporating your Heart Rate Reserve (HRR), which is your maximum heart rate minus your resting heart rate. It provides a more customized intensity target.

What is the fat burning heart rate zone?

The fat burning zone is generally Zone 2 (60% to 70% of your maximum heart rate or reserve). In this zone, your body burns a higher percentage of calories from fat, though higher intensities burn more total calories.

Does resting heart rate affect training zones?

Yes, if you use the Karvonen method. Individuals with a lower resting heart rate (indicating higher cardiovascular fitness) will have wider, more personalized heart rate zone ranges.

What is Zone 2 training and why is it popular?

Zone 2 training (60-70% intensity) is low-intensity aerobic training. It stimulates mitochondrial density and builds a strong aerobic base without putting excessive fatigue on the nervous system.

Should I adjust my heart rate zones if I take beta-blockers?

Yes. Beta-blockers and other cardiac medications suppress heart rate response. If you are taking these medications, standard age-based formulas are not valid, and you should consult a doctor.

About the Heart Rate Zone Calculator

A heart rate zone calculator helps fitness enthusiasts, athletes, and patients establish personalized target training ranges for cardiovascular exercise. Training within specific heart rate zones allows you to optimize physiological adaptations, such as fat oxidation, aerobic endurance, lactate threshold, or anaerobic capacity. Rather than relying on rigid, one-size-fits-all percentages, this tool supports multiple peer-reviewed maximal heart rate formulas—Fox, Tanaka, and Gellish—and implements the gold-standard Karvonen method. By factoring in your resting heart rate, the Karvonen method calculates target zones based on your Heart Rate Reserve (HRR), adapting the intensity to your individual cardiovascular fitness level.

Mathematical Formula & Logic

Maximal Heart Rate (MHR) Estimation: 1. Fox Formula: MHR = 220 - Age 2. Tanaka Formula: MHR = 208 - (0.7 × Age) 3. Gellish Formula: MHR = 207 - (0.7 × Age) Heart Rate Zone Calculations: - Maximum Heart Rate Method (Standard): Zone Heart Rate = MHR × Intensity% - Karvonen Method (Heart Rate Reserve): Heart Rate Reserve (HRR) = MHR - Resting Heart Rate (RHR) Zone Heart Rate = (HRR × Intensity%) + RHR Target Intensity Zones: - Zone 1 (Active Recovery): 50% to 60% - Zone 2 (Aerobic / Fat Burn): 60% to 70% - Zone 3 (Tempo / Endurance): 70% to 80% - Zone 4 (Lactate Threshold): 80% to 90% - Zone 5 (Anaerobic / Redline): 90% to 100%

Step-by-Step Example

Calculate the target heart rate range for Zone 2 (60% to 70% intensity) using the Karvonen method with the Fox formula for a 30-year-old individual with a resting heart rate of 60 BPM: 1. Estimate Maximal Heart Rate (MHR) using Fox: MHR = 220 - 30 = 190 BPM 2. Compute Heart Rate Reserve (HRR): HRR = MHR - RHR = 190 - 60 = 130 BPM 3. Calculate the lower limit of Zone 2 (60% intensity): HR_lower = (130 × 0.60) + 60 = 78 + 60 = 138 BPM 4. Calculate the upper limit of Zone 2 (70% intensity): HR_upper = (130 × 0.70) + 60 = 91 + 60 = 151 BPM 5. Zone 2 training target range is 138 BPM to 151 BPM (rounded via Banker's rounding).

Reference Data & Values

methodzone 1zone 2zone 3zone 4zone 5
Max Heart Rate (Standard)MHR × 0.50 - 0.60MHR × 0.60 - 0.70MHR × 0.70 - 0.80MHR × 0.80 - 0.90MHR × 0.90 - 1.00
Karvonen (HRR)(HRR × 0.50) + RHR(HRR × 0.60) + RHR(HRR × 0.70) + RHR(HRR × 0.80) + RHR(HRR × 0.90) + RHR

Frequently Asked Questions

Heart rate zones are ranges of heartbeats per minute (BPM) that correspond to different levels of exercise intensity. Training in different zones stimulates distinct physiological adaptations, such as fat burning, aerobic endurance, or anaerobic threshold capacity.
The Karvonen method calculates target training heart rates using the Heart Rate Reserve (HRR), which is the difference between your maximal heart rate and resting heart rate. By factoring in your resting heart rate, it provides a more personalized and accurate representation of cardiovascular workload than standard percentage calculations.
The traditional Fox formula (220 - age) is widely used but has been shown to overestimate maximal heart rate in younger adults and underestimate it in older populations. The Tanaka (208 - 0.7 * age) and Gellish (207 - 0.7 * age) formulas are based on more recent, rigorous clinical research and offer superior accuracy across different age groups.
Heart Rate Reserve is the range between your resting heart rate and your estimated maximum heart rate (HRR = MHR - RHR). It represents the reserve capacity available for exercise exertion.
A lower resting heart rate indicates higher cardiovascular efficiency. Factoring it into the Karvonen method shifts your training zones down, ensuring you do not overtrain, while a higher resting heart rate adjusts the zones upward so you work out at a sufficient intensity.
Zone 2 (60% to 70% of Heart Rate Reserve or maximum heart rate) is traditionally called the "fat-burn zone" because the body burns a higher percentage of calories from fat relative to carbohydrates. However, higher-intensity training burns more total calories overall.
For maximum accuracy, measure your resting heart rate first thing in the morning when waking up, before getting out of bed. Average this value over 3 to 5 days to establish a stable baseline, and re-measure every few months as your fitness level changes.
Maximal heart rate formulas are generally applied similarly across genders, though some specialized research suggests minor variations. Using formulas that incorporate resting heart rate (like Karvonen) naturally adjusts for individual gender-based and fitness-based differences.