About the target heart rate calculator
This calculator estimates your maximum heart rate and breaks it into five training zones, from easy warm-up effort to maximum. If you enter a resting heart rate, it uses the Karvonen (heart rate reserve) method, which tailors the zones to your fitness.
Heart rate zones help you pace workouts, but an estimated maximum is only an estimate. Use perceived effort alongside the numbers.
Who should use the target heart rate calculator
- Runners, cyclists and gym users structuring cardio sessions.
- People who wear a heart-rate monitor and want sensible zones to compare against.
- Anyone who has tested their own maximum and wants zones based on it.
How to use the target heart rate calculator: what each input means
- Age
- Used to estimate maximum heart rate.
- Maximum heart rate source
- Estimate from age, or enter a value from a supervised test.
- Formula
- Haskell & Fox (220 − age), Tanaka (208 − 0.7 × age) or Nes (211 − 0.64 × age).
- Resting heart rate
- Optional. Measure on waking, before getting up. When provided, zones use the Karvonen method.
How the target heart rate calculator works: method and formula
Without a resting heart rate, each zone is a percentage of your maximum. With a resting heart rate, the calculator uses heart rate reserve (maximum minus resting): target heart rate = resting + intensity × reserve. The five zones are 50–60%, 60–70%, 70–80%, 80–90% and 90–100%.
Maximum heart rate formulas are population averages with large individual variation, so a young fit person might be well above or below the estimate.
- Haskell & Fox
- HRmax = 220 − age
- Tanaka
- HRmax = 208 − 0.7 × age
- Nes
- HRmax = 211 − 0.64 × age
- Karvonen
- Target = resting HR + intensity × (HRmax − resting HR)
How to read your target heart rate calculator result
Zone 1–2 feels easy and is used for warm-ups, recovery and long steady sessions; zones 3–4 are moderate to hard; zone 5 is maximum effort and is only sustainable for short bursts. Use the talk test as a cross-check: in easy zones you can hold a conversation.
Medications (for example beta-blockers), heat, caffeine, illness and fatigue can all change heart rate. If you have a heart condition, speak to your doctor before exercising by heart-rate targets.
Target Heart Rate Calculator worked example
A 36-year-old with a resting heart rate of 70 beats per minute, using 220 − age.
- Maximum heart rate = 220 − 36 = 184 bpm.
- Heart rate reserve = 184 − 70 = 114 bpm.
- Zone 3 (70–80%) with Karvonen: 70 + 0.70 × 114 = 150 bpm to 70 + 0.80 × 114 = 161 bpm.
- Without a resting rate, Zone 3 would be 129 to 147 bpm.
Maximum 184 bpm; Zone 3 is 150–161 bpm with the Karvonen method.
Practical uses of the target heart rate calculator
- Setting easy and hard session targets for a running plan.
- Checking whether an easy run is really easy.
- Comparing formulas when you know your measured maximum.
Assumptions and limitations of this calculator
- Age-based maximum heart rate formulas can be off by 10 or more beats per minute for an individual.
- Zones are guidelines; they are not medical targets. If you take heart medication or have a heart condition, ask your doctor before using them.
- Not a substitute for a supervised exercise test.
This calculator is for general information and education only. It is not medical advice, a diagnosis or a treatment plan. Results are estimates based on population formulas and cannot account for your individual health. If you have a medical condition, are pregnant, are under 18, or are planning a major change to your diet or exercise, speak to a doctor or registered dietitian first.