Heart Rate Zone Calculator
Enter your age and, optionally, your resting heart rate to see your estimated maximum heart rate and five training zones in beats per minute.
Measure it in the morning before getting up, for one full minute.
Your 5 heart rate zones
| Zone | Intensity | Heart rate | What it trains |
|---|
Max heart rate by formula
| Formula | Equation | Max HR |
|---|
For information only – not medical advice. Age formulas can be off by 10–20 bpm for an individual. If you have a heart condition, take medication that affects heart rate or are new to exercise, talk to a doctor first.
How to use the Heart Rate Zone Calculator
- Enter your age and sex.
- Choose a max heart rate formula, or pick "I know my max heart rate" and enter a measured value.
- Pick the zone method: percent of max, or Karvonen with your resting heart rate.
- Press Calculate zones to see the five zones in bpm, the chart and a formula comparison.
- Type a heart rate from your watch to see which zone it is in.
Max heart rate formulas
Your maximum heart rate (HRmax) is the fastest your heart can beat during all-out effort. It is best measured in a supervised test, but most people estimate it from age:
| Formula | Equation | Age 40 example | Notes |
|---|---|---|---|
| Fox (1971) | 220 − age | 180 bpm | Simple and popular, but not based on rigorous data |
| Tanaka (2001) | 208 − 0.7 × age | 180 bpm | Meta-analysis of 18,000+ adults; more accurate for older people |
| Gulati (2010) | 206 − 0.88 × age | 171 bpm | Derived from 5,437 women; recommended for women |
| Nes (2013) | 211 − 0.64 × age | 185 bpm | HUNT fitness study of healthy men and women |
Percent of max vs the Karvonen method
The percent of max method simply multiplies HRmax by each zone percentage: zone 2 for a 185 bpm max is 0.6 × 185 to 0.7 × 185 = 111–130 bpm.
The Karvonen method uses your heart rate reserve (HRR = HRmax − resting HR) and adds your resting rate back: target = resting HR + HRR × intensity. With a 185 bpm max and a resting rate of 60 bpm, HRR is 125, so 70% intensity is 60 + 0.7 × 125 = 148 bpm. Because it accounts for fitness (a lower resting rate), Karvonen zones are usually higher and more personal.
The five training zones
| Zone | Intensity | Feels like | Typical use |
|---|---|---|---|
| 1 · Very light | 50–60% | Easy, relaxed breathing | Warm-up, recovery days |
| 2 · Light | 60–70% | Comfortable, can chat | Long, easy endurance sessions |
| 3 · Moderate | 70–80% | Steady, slightly breathless | Tempo and aerobic workouts |
| 4 · Hard | 80–90% | Hard, short sentences | Threshold intervals |
| 5 · Maximum | 90–100% | All-out, cannot talk | Short sprints and VO₂max intervals |
Many endurance plans follow an 80/20 split: about 80% of training time in zones 1–2 and 20% in zones 3–5.
Frequently asked questions
What is my target heart rate?
For moderate exercise, the American Heart Association suggests about 50–70% of your maximum heart rate, and 70–85% for vigorous exercise. The table shows these as bpm ranges for your age.
Which max heart rate formula is most accurate?
Studies show Tanaka (208 − 0.7 × age) is more accurate than 220 − age, especially for people over 40. For women, Gulati (206 − 0.88 × age) fits better. Any formula can be off by 10–20 bpm for an individual.
What is the Karvonen method?
It calculates zones from your heart rate reserve, the difference between your maximum and resting heart rate: target = resting + (max − resting) × intensity. It gives more personal zones because it includes your fitness level.
What heart rate is zone 2?
Zone 2 is 60–70% of max heart rate. For a 35-year-old using the Tanaka formula (max 184 bpm) it is about 110–129 bpm. With the Karvonen method and a resting rate of 60 bpm it is about 134–147 bpm.
Is the fat burning zone real?
At lower intensity (zones 2–3) a larger share of energy comes from fat, but higher intensities burn more total calories. For fat loss, total energy balance matters most.
Is this medical advice?
No. These are general estimates for information only. Beta blockers and other medications change heart rate. Check with a doctor before starting a hard training plan, especially with a heart condition.