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Free online heart rate zones calculator

Heart rate training zones divide exercise intensity into five bands tied to specific beats per minute. This calculator shows your five zones using the Karvonen or % max HR method.

Calculation method
About this calculator

How to use

  1. Enter your age — used to estimate max HR with 220 − age.
  2. Enter your resting heart rate (measure it first thing in the morning for accuracy).
  3. Choose Karvonen (recommended) or % Max HR.
  4. The five training zones appear instantly in the table below.

The formulas

Maximum heart rate (standard)

Max HR = 220 − age

Karvonen method

HR Reserve = Max HR − Resting HR
Target HR  = (HR Reserve × intensity%) + Resting HR

Percentage of max HR

Target HR = Max HR × intensity%

Zone intensities:

ZoneNameIntensity range
1Recovery50–60%
2Aerobic60–70%
3Tempo70–80%
4Lactate Threshold80–90%
5Max Effort90–100%

Worked example

Age 30, resting HR 60 bpm, Karvonen method:

  • Max HR = 220 − 30 = 190 bpm
  • HR Reserve = 190 − 60 = 130 bpm
  • Zone 1: 50% × 130 + 60 = 125 bpm to 60% × 130 + 60 = 138 bpm
  • Zone 2: 138–151 bpm
  • Zone 3: 151–164 bpm
  • Zone 4: 164–177 bpm
  • Zone 5: 177–190 bpm

Notes

  • The 220 − age formula is an estimate with a standard deviation of about 10–12 bpm. Individual max HR can vary significantly.
  • For accurate zones, consider a field test: run all-out for 1 mile and note your peak heart rate.
  • A heart rate monitor or GPS watch will give more reliable in-workout data than perceived exertion alone.

Frequently asked

What are heart rate training zones?
Training zones divide exercise intensity into five bands, from light recovery (Zone 1) to maximum effort (Zone 5). Each zone targets different energy systems — fat burning, aerobic capacity, lactate threshold — so athletes can train smarter by targeting the right zone for each session.
What is the Karvonen method?
The Karvonen formula uses Heart Rate Reserve (HRR = max HR − resting HR) to calculate zones: Target HR = (HRR × intensity%) + resting HR. Because it accounts for your resting heart rate, it produces more personalized zones than a simple percentage of max HR.
What is the percentage of max HR method?
The simpler method calculates zones as a straight percentage of your estimated maximum heart rate (220 − age). It does not account for resting heart rate, so it may be less accurate for trained athletes with a low resting HR.
How is max heart rate estimated?
This calculator uses the standard formula: max HR = 220 − age. You can also enter a known max HR if you have a recent lab or field test result.
Which method should I use?
For trained athletes or anyone with a resting heart rate well below average, the Karvonen method is more accurate. For general fitness guidance, either method works. If you have had a VO2 max test, use those laboratory zones instead.
How do I use the Share button?
Share copies the plain page URL. Share with my numbers copies a URL with your age, resting HR, and method included, so anyone can open the link and see your zones.

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