Heart Rate Zones Calculator

Your max heart rate and all five training zones — from easy fat-burning cardio to max effort intervals.

yrs
bpm

What are heart rate training zones?

Heart rate zones divide the range between rest and your maximum heart rate into five intensity bands, each with a different training effect — from easy recovery work to all-out intervals. This heart rate zone calculator estimates your max heart rate and builds all five zones, using the more accurate Karvonen method if you provide your resting heart rate.

How it works

Max heart rate is estimated with the Tanaka formula: 208 − 0.7 × age, derived from a meta-analysis of 351 studies and more accurate than the older "220 − age" rule, which drifts badly for older adults. Zones are then set two ways:

  • Percent of max (no resting HR): each zone is a straight percentage of your max heart rate.
  • Karvonen method (with resting HR): zones are percentages of your heart rate reserve (max − resting) added back on top of resting. Because it accounts for your fitness level, it fits real training intensities better.

What each zone does

  • Zone 1 (50–60%): recovery — promotes blood flow without adding fatigue
  • Zone 2 (60–70%): endurance base and fat oxidation — where most cardio volume belongs; you can hold a conversation
  • Zone 3 (70–80%): aerobic tempo — comfortably hard
  • Zone 4 (80–90%): lactate threshold — hard, sustainable in blocks of minutes
  • Zone 5 (90–100%): maximal efforts — short intervals only

Frequently asked questions

Is Zone 2 really the "fat burning zone"?

Zone 2 burns the highest proportion of calories from fat, but harder zones burn more total calories. For fat loss, total energy balance wins; Zone 2's real value is building your aerobic base with minimal recovery cost.

My max HR feels different from the formula — which is right?

Yours. Formulas carry a ±10 bpm standard deviation. If you've seen a genuine max in a race or field test, use that number mentally and shift the zones accordingly.

References

  1. Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 2001;37(1):153–156.
  2. Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate: a longitudinal study. Ann Med Exp Biol Fenn. 1957;35(3):307–315.

Related

These results are estimates for healthy adults and are not medical advice. Consult a health professional before making major changes to your diet or training.

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