Calculate heart rate zone

Turn a measured resting pulse and an age-predicted maximum into five heart-rate-reserve training bands.

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ToolHeart Rate Zone Calculator
Input
Output
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How it works

Tanaka's 208 − 0.7 × age estimates maximum heart rate, and subtracting resting bpm gives the available reserve. Each boundary takes 50%, 60%, 70%, 80%, 90%, or 100% of that reserve and adds resting bpm back; 220 − age is retained only as a comparison estimate.

Formula
zone boundary = resting bpm + intensity × (predicted maximum − resting bpm)
  • Resting bpm is required because assuming 60 would shift every boundary for someone whose measured value differs.
  • The five bands are percentage bins, not lactate or ventilatory thresholds measured in a laboratory.

Worked example

A 30 year old with a resting rate of 60
Zones from the heart rate reserve
Input
											Age: 30
Resting heart rate: 60
Output
												Max heart rate: 187
Max heart rate220 age: 190
Heart rate reserve: 127
Recovery: 124 to 136 bpm
Endurance: 136 to 149 bpm
Aerobic: 149 to 162 bpm
Threshold: 162 to 174 bpm
Maximum: 174 to 187 bpm

When to use this

Endurance plans assign easy and hard sessions by reserve percentage, sports watches accept custom bpm boundaries, and graded exercise tests compare a measured maximum with age-predicted values.

Edge cases

  • A resting pulse taken after caffeine, exercise, illness, or while standing is used unchanged and shifts all five bands.
  • Beta blockers and other rate-limiting medicines are not represented, so their altered exercise response is not corrected.
  • A measured maximum may differ from both age equations; both displayed values remain labeled as predictions rather than measurements.

References