Heart Rate Zone Calculator

Calculate Heart Rate Zones

bpm

Measure first thing in the morning, before getting up

Estimated Max Heart Rate

190 bpm

Zone 1 · Recovery

128–140

50–60%

Zone 2 · Fat Burn

140–153

60–70%

Zone 3 · Cardio

153–165

70–80%

Zone 4 · Threshold

165–178

80–90%

Zone 5 · Peak

178–190

90–100%

See how this is calculated

How This Calculation Works

This calculator estimates your maximum heart rate using the classic formula: 220 minus your age. While simple, it's a widely used starting point that correlates reasonably well with actual maximum heart rate for most people, though individual variation of ±10-15 beats per minute is common.

Using your resting heart rate and estimated max, the calculator applies the Karvonen method to define five training zones as percentage ranges of your heart rate reserve (the difference between max and resting heart rate). Each zone corresponds to a different training effect: Zone 1 supports recovery and easy movement, Zone 2 builds aerobic base and burns a higher percentage of fat for fuel, Zone 3 improves cardiovascular fitness, Zone 4 raises your lactate threshold, and Zone 5 develops maximum performance and speed.

Training across different zones — rather than always at the same intensity — is a core principle behind most structured endurance and fitness programs, since each zone stimulates different physiological adaptations.

Common Mistakes to Avoid

  • Assuming the 220-minus-age formula is exact. It's a population average with meaningful individual variation. If you have access to a supervised max heart rate test or have observed your true max during intense effort, use that instead for more accurate zones.
  • Training too hard, too often. A common mistake is spending most workouts in Zone 3-4 ("gray zone" training) instead of following the 80/20 principle many endurance coaches recommend — roughly 80% easy (Zone 1-2) and 20% hard (Zone 4-5) for balanced, sustainable progress.
  • Ignoring resting heart rate changes. Your resting heart rate can drop as cardiovascular fitness improves, or rise temporarily due to illness, stress, or poor sleep — recheck it periodically for more accurate zone calculations.
  • Not accounting for medications. Certain medications, particularly beta-blockers, significantly lower heart rate response to exercise. If you take heart-rate-affecting medication, discuss appropriate training intensity with your doctor rather than relying solely on these zones.

Worked Example

Scenario: A 30-year-old with a resting heart rate of 65 bpm.

Step 1 — Max heart rate: 220 − 30 = 190 bpm.

Step 2 — Heart rate reserve: 190 − 65 = 125 bpm.

Step 3 — Zone 2 (60-70%) using Karvonen: Low end: 65 + (125 × 0.60) = 140 bpm. High end: 65 + (125 × 0.70) = 152.5 bpm.

Result: This person's fat-burning Zone 2 range is approximately 140–153 bpm.

Frequently Asked Questions

What is the most accurate way to find my max heart rate?
A supervised graded exercise test in a lab or clinical setting is the gold standard, but it's not practical for most people. The 220-minus-age formula is a reasonable free estimate; if you've observed a genuinely maximal heart rate during hard effort (like a race finish), that observed number is often more accurate than the formula.
What is heart rate reserve and why does it matter?
Heart rate reserve is the gap between your maximum and resting heart rate — it represents your heart's full working range. The Karvonen method used here calculates zones as a percentage of this reserve added to your resting rate, which is generally considered more personalized than simply using percentages of max heart rate alone.
Which zone should I train in most often?
Many endurance coaches recommend spending roughly 80% of training time in low-intensity Zones 1-2, with the remaining 20% in higher-intensity Zones 4-5, and comparatively little time in the moderate "Zone 3" range. This approach, often called polarized training, is associated with strong long-term fitness gains while managing fatigue and injury risk.
Why is my resting heart rate important for this calculation?
Resting heart rate reflects your baseline cardiovascular fitness and is a key input to the Karvonen method, which produces more personalized zones than simply using flat percentages of max heart rate. A lower resting heart rate (often seen in fitter individuals) shifts your training zones to reflect your larger heart rate reserve.

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