Toolverge

Heart Rate Zone Calculator

A heart rate zone calculator finds the target heart rate ranges for different training intensities — warm-up, fat burn, cardio, hard, and maximum effort. Toolverge uses the Karvonen method, which factors in your resting heart rate (not just age), giving more personalized zones than a simple percentage of age-predicted max.

Educational estimate only. Results are not medical, legal, or financial advice. Confirm important decisions with a qualified professional.

Heart rate zones

  • Warm up: 125–138 bpm
  • Fat burn: 138–151 bpm
  • Cardio (aerobic): 151–164 bpm
  • Hard (anaerobic): 164–177 bpm
  • Maximum effort: 177–190 bpm

How it works

  1. Enter your age and resting heart rate.
  2. Optionally override the estimated max heart rate (220 − age).
  3. Read all five training zones, in beats per minute, on the tape.

Formula Heart rate reserve (HRR) = Max HR − Resting HR; Zone target = Resting HR + HRR × intensity %

Frequently asked questions

What is the Karvonen method?

It calculates target heart rate as resting HR plus a percentage of heart rate reserve (max HR minus resting HR), rather than a flat percentage of max HR alone — it accounts for your fitness level via resting heart rate.

How is max heart rate estimated?

The common estimate is 220 minus your age, though this is population-average and can be off by ±10-12 bpm for an individual — use the override field if you have a lab-tested max.

What is the "fat burn" zone?

Roughly 60-70% of heart rate reserve — lower intensity that’s sustainable for longer, though total calories burned still depends on duration, not just zone.

How do I measure my resting heart rate?

Count your pulse for 60 seconds right after waking up, before getting out of bed, for the most accurate reading.

Is this medical advice?

No — consult a doctor before starting an intense exercise program, especially with any heart condition.