How to use the target heart rate calculator
- Enter your age.
- Choose a maximum heart rate formula: the classic 220 − age, or the Tanaka formula.
- Optionally enter your resting heart rate. Count your pulse for a full minute in the morning before you get up, on a few days, and use the average.
- Read your target range, your moderate and vigorous ranges, and the zone table.
How target heart rate is calculated
The 220 − age rule is the simplest and most widely used estimate. The Tanaka formula comes from a 2001 analysis of 351 studies of maximum heart rate (Tanaka, Monahan and Seals, Journal of the American College of Cardiology). It gives slightly higher maximums for older adults and slightly lower ones for younger people. The two agree at age 40.
The Karvonen method works on your heart rate reserve, the gap between your resting and maximum rates. Because it starts from your own resting rate, it adjusts the zones for fitness. A fit person with a low resting rate gets a wider working range.
The American Heart Association describes about 50% to 70% of maximum heart rate as moderate intensity and 70% to 85% as vigorous. That is the 50% to 85% target range shown at the top.
Worked example
The calculator's default is a 40-year-old using 220 − age, with no resting heart rate:
- Maximum heart rate: 220 − 40 = 180 bpm (Tanaka: 208 − 0.7 × 40 = 180 bpm, the same)
- Bottom of the target range: 180 × 0.50 = 90 bpm
- Top of the target range: 180 × 0.85 = 153 bpm, so the target is 90 – 153 bpm
- Moderate: 90 to 126 bpm; vigorous: 126 to 153 bpm
Add a resting rate of 60 bpm and the Karvonen method takes over. The heart rate reserve is 180 − 60 = 120 bpm, so the range becomes 60 + 0.50 × 120 = 120 bpm up to 60 + 0.85 × 120 = 162 bpm.
Heart rate zones
| Zone | % of max | At age 40 (max 180) | What it trains |
|---|---|---|---|
| 1 | 50–60% | 90–108 bpm | Recovery, warm-up |
| 2 | 60–70% | 108–126 bpm | Aerobic base, fat use, endurance |
| 3 | 70–80% | 126–144 bpm | Aerobic fitness |
| 4 | 80–90% | 144–162 bpm | Lactate threshold, race pace |
| 5 | 90–100% | 162–180 bpm | Speed and maximum effort, short bursts |
This five-zone model is a common coaching convention rather than a medical standard, and zone names vary between watch brands and coaches. Most training for health and endurance happens in zones 2 and 3. Zones 4 and 5 are for shorter, harder sessions once you have a base.
Limits of age-based formulas
Any formula based only on age is an average for large groups. Your own maximum can easily be 10 bpm or more above or below the estimate, which shifts every zone. A supervised exercise test is the only accurate way to measure it. Some medicines, especially beta blockers, lower your heart rate during exercise, so the targets may be too high. If you take heart or blood pressure medicine, have a heart condition, or are starting exercise after a long break, ask your doctor what intensity is safe for you. Stop and get help if you feel chest pain, faintness or unusual breathlessness.
Frequently asked questions
Which formula should I use?
For most people either is fine. Tanaka is a little more accurate on average, especially past middle age, where 220 − age tends to underestimate. If your heart rate regularly goes above your estimated maximum during hard efforts without problems, your real maximum is simply higher.
How do I check my heart rate during exercise?
Use a chest strap or a watch, or count your pulse at the wrist or neck for 15 seconds and multiply by 4. Wrist sensors can lag during intervals and lose accuracy at high intensity, so chest straps are more reliable for zone training.
Is it bad to exercise above my target range?
Not for healthy people in short bursts; that is what interval training does. Staying near your maximum for long periods is hard and not needed for health. If you have a heart condition, stay within the limits your doctor gives you.
What is a normal resting heart rate?
For most adults it is between 60 and 100 beats a minute. Fit people and athletes are often lower, sometimes in the 40s. A resting rate that is unusually high or low for you, especially with symptoms such as dizziness, is worth discussing with your doctor.
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Results are estimates for general information and are not medical advice. Talk to a doctor or other qualified professional about your health. See our disclaimer.