Target Heart Rate Calculator

Find your target heart rate zones for every level of exercise intensity — from active recovery to VO2 max. Uses the Karvonen (Heart Rate Reserve) formula for personalized zones based on your age and resting heart rate. Includes both 5-zone and 3-zone systems.

bpm (measure first thing in morning)

Your Heart Rate Zones

Max Heart Rate —
Resting Heart Rate —
Heart Rate Reserve —
Fat Burn Zone (50–70%) —

5-Zone Training System (Karvonen)

Zone% IntensityBPM RangeTraining EffectRPE

Simple 3-Zone System (% of Max HR)

Zone% Max HRBPM RangeDescription

Max HR Formula Comparison

FormulaMax HR (bpm)Fat Burn Zone

Understanding Heart Rate Training Zones

Training in specific heart rate zones allows you to target different physiological adaptations. The two most common systems are the 5-zone model (used by most coaches) and the 3-zone model (simpler, used in research).

The Karvonen (Heart Rate Reserve) Method

The Karvonen formula is more accurate than simple percentage of max HR because it accounts for your fitness level through resting heart rate. A trained athlete with a resting HR of 45 bpm and an untrained person with a resting HR of 80 bpm have very different training ranges even at the same age.

Formula: Target HR = ((Max HR − Resting HR) × % Intensity) + Resting HR

Which Formula for Max HR?

  • 220 − Age: Standard formula, simple but overestimates for older adults
  • 208 − 0.7 × Age (Tanaka): More accurate for adults, especially 40+
  • 206.9 − 0.67 × Age (Gellish): Research-based, good across all ages

RPE Scale

RPE (Rating of Perceived Exertion) on a 6–20 scale: Zone 1 = RPE 11–12 (very light), Zone 2 = 12–13 (light), Zone 3 = 13–15 (moderate), Zone 4 = 15–17 (hard), Zone 5 = 17–20 (very hard to maximal).

Frequently Asked Questions

Related Reading

Target heart rate (THR) is the heart rate range you should aim for during aerobic exercise to achieve specific training benefits. Exercising too far below your target zone provides little cardiovascular benefit; too far above can be unsustainable or risky. Most fitness guidelines recommend exercising at 50–85% of your maximum heart rate, with the specific range depending on your fitness goal.

The simplest check is the talk test: if you can speak in full sentences easily, you are below Zone 3 (under ~70% max HR). If you can say a few words but not full sentences, you are in the moderate-to-vigorous range (70–85%). If you cannot speak at all, you are above 85% max HR. A heart rate monitor gives precise feedback, with chest straps being more accurate than wrist optical sensors.

No — periodized training that varies intensity across sessions produces better results than always training at the same effort. Most endurance coaches recommend spending 70–80% of total training time at low intensity (Zone 1–2) and 20–30% at moderate to high intensity (Zone 3–5). This approach builds aerobic base while allowing adequate recovery and is supported by research on both recreational and elite athletes.

Formula sources & accuracy standards: Calculator Methodology · Editorial Policy