Heart Rate Zone Calculator
Find your maximum heart rate and personalised training zones using your age and resting heart rate (Karvonen method).
Max HR = 220 − age. Zones use the Karvonen formula with your resting heart rate. Estimates only — not medical advice.
What Is a Heart Rate Zone Calculator
A Heart Rate Zone Calculator estimates your maximum heart rate and the heart rate ranges, or zones, you should aim for during different kinds of exercise. By entering your age and resting heart rate, you get target beats per minute for fat burning, cardio fitness and peak effort.
Training in the right zone helps you exercise with purpose. Stay too low and you may not build fitness; push too high for too long and you risk burning out. Zones give you simple targets so easy runs stay easy and hard sessions are genuinely hard. This tool gives an estimate for general fitness and is not medical advice; speak to a doctor before starting intense exercise, especially if you have any heart condition.
How It Works
The calculator uses two well known formulas:
- Maximum heart rate = 220 minus your age. This is a simple population estimate of the fastest your heart can safely beat.
- Karvonen target = ((maxHR minus restingHR) times intensity) plus restingHR. This heart rate reserve method personalises zones to your fitness by using your resting heart rate.
The standard training zones are then mapped to intensity ranges: fat burn at 60 to 70 percent, cardio at 70 to 80 percent, and peak at 80 to 90 percent of your reserve. Lower zones suit warm ups and long easy efforts, while higher zones build speed and power.
Worked Example
Take a 30 year old with a resting heart rate of 70 bpm. Maximum heart rate is 220 minus 30 = 190 bpm. The heart rate reserve is 190 minus 70 = 120 bpm. For the cardio zone at 70 to 80 percent: the lower bound is (120 times 0.70) plus 70 = 154 bpm, and the upper bound is (120 times 0.80) plus 70 = 166 bpm. So this person should aim for roughly 154 to 166 bpm during cardio training. Remember this is an estimate, not medical advice.
Training With Heart Rate Zones
Most balanced plans spend the majority of time in lower, easy zones to build an aerobic base, with shorter bursts in the cardio and peak zones to sharpen fitness. A common mistake is running every session at a moderate-hard effort, which leaves you tired without the benefits of either true rest or true intensity.
Measure your resting heart rate first thing in the morning before getting up for the most accurate figure, since it changes with stress, sleep and caffeine. The 220 minus age formula is a rough guide and can be off by 10 to 15 bpm for many people, so treat the zones as a starting point and adjust to how you feel. If a zone feels impossible or far too easy, your true maximum may differ from the estimate.
Frequently Asked Questions
The common estimate is 220 minus your age. For a 30 year old that is 190 bpm. It is a population average and can vary by 10 to 15 bpm between individuals, so use it as a guide rather than an exact figure.
The Karvonen method personalises zones using your heart rate reserve, which is maximum heart rate minus resting heart rate. The target is (reserve times intensity) plus resting heart rate, giving ranges tailored to your fitness.
The usual zones are fat burn at 60 to 70 percent, cardio at 70 to 80 percent, and peak at 80 to 90 percent of your heart rate reserve. Lower zones suit easy efforts and higher zones build speed.
Measure it first thing in the morning before getting up, counting your pulse for a full minute or using a fitness tracker. Avoid caffeine and stress beforehand, since both raise the reading.
The fat burn zone uses a higher share of fat for fuel, but higher intensity work burns more total calories. For weight loss, total calories burned and your diet matter most, so a mix of zones works well.
No. This calculator gives a general fitness estimate only and is not medical advice. If you have a heart condition or are new to intense exercise, consult a doctor before training in higher zones.