Health calculator

Heart Rate Zone Calculator, Fat Burn, Cardio & Peak Training Zones

Find your 5 target heart rate zones for fat burn, cardio, and peak training. Uses standard and Karvonen formulas based on your age and resting heart rate.

According to the U.S. Internal Revenue Service and the National Institute of Standards and Technology, more than 1,000 published rate, threshold, and conversion reference values update annually across tax, mortgage, and engineering domains that CalcMesh formulas trace to. The CalcMesh registry listed 53 calculators across 9 categories as of August 2026. See our methodology for derivation standards and refresh cadence.

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years
BPM

Measure first thing in the morning for best accuracy

Max Heart Rate

–

Estimated maximum

Heart Rate Reserve

–

Max minus resting

Training Zones

Zone 1 Recovery
50-60%

–

Warm-up, cool-down, active recovery

Zone 2 Fat Burn
60-70%

–

Base endurance, easy conversation pace

Zone 3 Aerobic
70-80%

–

Moderate effort, improves cardiovascular fitness

Zone 4 Anaerobic
80-90%

–

Hard effort, increases speed and power

Zone 5 VO2 Max
90-100%

–

Maximum effort, short bursts only

How CalcMesh calculates heart-rate zones

We estimate maximum heart rate as roughly 220 minus your age, then derive training zones as percentages of that maximum, the approach used by the American Heart Association. For more precision we also support the Karvonen method using resting heart rate.

These zones are population estimates that vary by individual; the formulas we use are documented in our methodology.

Heart Rate Training Guide

What Each Zone Does

  • Zone 1 (Recovery): Very light effort. Used for warm-ups, cool-downs, and recovery between hard workouts. Builds the foundation of aerobic fitness without fatigue.
  • Zone 2 (Fat Burn): Comfortable effort where you can hold a full conversation. Builds aerobic base, improves fat metabolism, and is sustainable for long durations. This is where most endurance training should occur.
  • Zone 3 (Aerobic): Moderate effort, slightly harder to hold a conversation. Improves overall cardiovascular efficiency and is the transition zone between easy and hard training.
  • Zone 4 (Anaerobic): Hard effort, can only speak in short phrases. Builds lactate threshold, increases speed and power. Typically sustained for 10-30 minutes in intervals.
  • Zone 5 (VO2 Max): All-out effort, cannot speak. Builds maximum cardiovascular capacity. Only sustainable for 30 seconds to 3 minutes. Used sparingly in training.

Measuring Resting Heart Rate

For the most accurate resting heart rate:

  • Measure first thing in the morning before getting out of bed
  • Use a chest strap or pulse oximeter for accuracy
  • Take readings for 3-5 days and use the average
  • Avoid caffeine and alcohol the evening before

Training by Goal

  • Weight loss: Focus on Zones 2-3 with occasional Zone 4 intervals
  • Endurance: Spend 80% of time in Zones 1-2, 20% in Zones 3-4
  • Performance: Structured mix of all zones with emphasis on Zone 4-5 intervals and Zone 1-2 recovery
  • General health: 150 minutes per week in Zones 2-3

Standard vs. Karvonen Method

The Standard method calculates zones as simple percentages of max heart rate (220 - age). It is simpler but less personalized.

The Karvonen method uses your heart rate reserve (max HR minus resting HR) and adds back your resting HR. This produces more accurate zones because it accounts for your individual fitness level. A lower resting heart rate generally indicates better cardiovascular fitness.

Disclaimer: This calculator provides estimates for informational purposes only. Consult your healthcare provider before starting a new exercise program, especially if you have a heart condition or other health concerns.

After you get your zones

What to do with the numbers

  • Match your training zone to your actual goal from the by-goal list above - most endurance and general-health training should sit in Zone 2-3, not Zone 4-5, even though the hard zones feel more productive.
  • If you want more personalized zones, measure your resting heart rate over 3-5 mornings (before caffeine, before getting up) and re-run with the Karvonen method instead of the standard 220-minus-age formula.
  • Use the "can you hold a conversation" test from the zone descriptions as a real-time check during a workout - it is a more reliable in-the-moment gauge than watching a number on a wrist monitor.
  • If you have a heart condition or are new to structured exercise, get clearance from your doctor before training at Zone 4-5 intensities, this calculator estimates population zones, not a medical clearance.

Methodology & Assumptions

This screening tool implements published anthropometric or energy-balance formulas on the measurements you enter. Outputs are arithmetic aids, not clinical judgements—see cited references below.

How this body-metric node runs

Anthropometric and energy estimators implement published screening formulas. They are arithmetic aids, not clinical judgements. Published domain formulas govern the identities; when an agency updates rates or thresholds we refresh defaults and the page lastmod.

Frequently Asked Questions

What zone burns the most fat?
Zone 2 (60-70% max HR) burns the highest percentage of calories from fat, which is why it is called the "fat burn" zone. However, higher intensity zones burn more total calories per minute, which can lead to greater overall fat loss. For weight loss, a mix of Zone 2 endurance work and higher-intensity intervals is most effective. Consistency matters more than staying in a specific zone.
How do I find my max heart rate?
The simplest estimate is 220 minus your age, though this can be off by 10-15 beats per minute for individuals. A more accurate method is a supervised maximal exercise test with a cardiologist. Field tests, like running an all-out mile after warming up and checking your peak heart rate, provide a better personal estimate but carry risk for untrained individuals.
Is the 220-minus-age formula accurate?
The 220-minus-age formula is a rough average that works reasonably well at the population level but can be inaccurate by 10-15 BPM for individuals. Some people naturally have higher or lower max heart rates regardless of fitness level. If your training feels too easy or too hard based on the calculated zones, consider adjusting or getting a supervised max HR test.
How long should I train in each zone?
Training distribution depends on your goals. A general guideline is the 80/20 rule: spend 80% of training time in Zones 1-2 (easy aerobic) and 20% in Zones 3-5 (moderate to hard). For beginners, spend more time in Zone 2 building a base. For performance, include 1-2 high-intensity sessions per week in Zones 4-5, with adequate recovery between them.

This page identifies the inputs, method, and limitations behind its estimates. CalcMesh does not publish lender, insurer, provider, or plan fee schedules. Any monetary output is calculated from the inputs shown on the page, not a current quote. Compare a fee, rate, or term with the governing agreement or disclosure before a consequential decision. Calculator outputs are not professional advice. Body-metric outputs here apply published formulas to your measurements—no clinical record is assumed. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.

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Inputs, defaults, and authoritative sources
Input Default Source / authority
All inputs Domain-typical defaults Editorial methodology, CalcMesh 2026