Note: This calculator is for general adults, not for pregnancy dieting. If you are pregnant, please follow your doctor’s advice.

What Are Heart Rate Zones?

Heart rate zones are ranges of beats per minute (bpm) that match different training intensities. Instead of guessing how hard you are working, you check your pulse and see which zone you are in. Each zone trains the body differently: easy zones build endurance and aid recovery, while hard zones raise speed and power.

Most systems use five zones, based either on a percentage of your maximum heart rate, on your heart rate reserve, or on your lactate threshold heart rate. The calculator above supports all three, so you can compare them for yourself.

The 5 Heart Rate Zones Explained

Zone	% of max HR	Effort	Purpose
Zone 1: Recovery	50–60%	Very easy, like a gentle walk	Warm-up, cool-down, active recovery
Zone 2: Aerobic base	60–70%	You can speak in full sentences	Endurance, fat metabolism, building a base
Zone 3: Tempo	70–80%	Comfortably hard	Aerobic fitness and stamina
Zone 4: Threshold	80–90%	Hard, only short sentences	Raises the pace you can hold
Zone 5: Maximum	90–100%	All-out, cannot talk	Top-end speed, short intervals only

Running or cycling at any heart rate inside a zone has broadly a similar training effect, so you do not need to hit an exact number. Treat each zone as a band, not a target line.

Three Ways to Calculate Your Zones

1. Percentage of max heart rate

The simplest method multiplies your max heart rate by each zone percentage. If your estimated max is 184 bpm, Zone 2 (60–70%) is roughly 110–128 bpm. It needs only your age, but it ignores how fit you are.

2. Karvonen method (heart rate reserve)

The Karvonen formula includes your resting heart rate:

Zone bpm = ((Max HR − Resting HR) × intensity %) + Resting HR

With a max of 184 and a resting rate of 62, your reserve is 122 bpm and Zone 2 becomes about 135–146 bpm, noticeably higher than the simple percentage method. That is because a fitter person with a low resting rate has a bigger reserve to work with, and percentages of heart rate reserve have been shown to track percentages of VO₂max more closely than percentages of max heart rate.

3. Lactate threshold heart rate (LTHR)

Your lactate threshold is roughly the intensity above which fatigue builds quickly. Zones based on it do not depend on an age formula at all, which is helpful because age-predicted max heart rate can be off by 10–12 bpm for any individual. A common field test is a hard, steady 30-minute solo effort (a run, bike ride or similar), after which you take your average heart rate over the last 20 minutes as your LTHR. In the calculator, LTHR zones use these ranges: Zone 1 below 85%, Zone 2 85–89%, Zone 3 90–94%, Zone 4 95–99%, and Zone 5 100–106% of LTHR. This follows a widely used coaching model; treat it as a guide and rerun the test every few months as fitness changes.

Which method should you choose?

• Beginners: % of max HR, because it is quick and needs no testing.
• Anyone who knows their resting HR: Karvonen, for more personal zones.
• Regular runners and cyclists who can do a hard test: LTHR, which uses a measured number rather than an age formula.

How to Find Your Max Heart Rate

The old shortcut 220 − age is only a population average. Other formulas such as Tanaka (208 − 0.7 × age), Gulati (206 − 0.88 × age, for women), HUNT and Nes (211 − 0.64 × age) fit many people better. The calculator picks one for you or lets you compare them. If you have ever recorded a true all-out peak on a heart rate monitor, enter that number instead.

How to Measure Your Resting Heart Rate

Count your pulse for 60 seconds first thing in the morning, before getting out of bed or having caffeine. Repeat for three days and use the average. A lower resting rate usually reflects better cardiovascular fitness, though illness, poor sleep and stress can push it up.

Zone 2: Why Everyone Talks About It

Zone 2 is the steady, conversational pace where you build your aerobic base. It is often called the fat-burning zone because a larger share of your energy comes from fat at this intensity. Harder exercise burns more calories per minute, so Zone 2 is not magic for weight loss, but it is easy to recover from, which lets you train more often and for longer. A simple check: if you cannot speak in full sentences, you are probably above Zone 2.

How Much Time to Spend in Each Zone

Many endurance athletes follow the 80/20 principle: roughly 80% of training time at low intensity and about 20% at moderate to high intensity. The optional weekly planner in the calculator uses three illustrative splits for general health, endurance and fitness/fat loss. They are starting points, not prescriptions, so adjust for your schedule, recovery and goals.

Example: with 240 minutes a week on the general-health split, that is about 48 minutes in Zone 1, 144 in Zone 2, 36 in Zone 3, 12 in Zone 4 and none in Zone 5.

Check Your Zone During a Workout

1. Pause and find your pulse on your wrist or neck.
2. Count beats for 10 seconds and multiply by 6.
3. Or type your current bpm into the “Which zone am I in right now?” box in the calculator.
4. Speed up or slow down to move into the zone you planned.

Chest straps are generally more accurate than wrist sensors during intervals. Watches from brands such as Garmin and Polar let you enter custom zones, so you can copy your results across.

Why Your Heart Rate Can Differ From the Chart

• Heat, humidity and dehydration raise heart rate at the same effort.
• Caffeine, stress, poor sleep and illness raise it too.
• Altitude can lower max heart rate while making effort feel harder.
• Medicines such as beta-blockers blunt heart rate, so use perceived effort instead.
• Genetics: two healthy people of the same age can have max heart rates 20 bpm apart.

When in doubt, combine heart rate with how the effort feels, using the talk test as a quick cross-check.

Safety First

Stop and seek medical help if you notice chest pain or pressure, severe breathlessness, dizziness, fainting or an irregular heartbeat. Speak with a doctor before using high-intensity zones if you have a heart condition, high blood pressure, diabetes, are pregnant or are returning to exercise after a long break.

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Frequently Asked Questions

How do I calculate my heart rate zones?

Find your max heart rate (by formula or testing), then multiply by each zone percentage. For a more personal result, use the Karvonen method with your resting heart rate, or base the zones on your lactate threshold heart rate.

What heart rate is Zone 2?

Zone 2 is usually 60–70% of max heart rate. For someone with a max of 184 bpm that is about 110–128 bpm using simple percentages, or about 135–146 bpm with the Karvonen method and a resting rate of 62.

Is the Karvonen method better than percent of max?

It is usually more personal because it includes your resting heart rate, so fitter people get higher zones than the simple method gives them. Neither fully replaces a measured max or threshold.

How many heart rate zones are there?

Five is the most common model, though some systems use three or seven. The calculator offers a 5-zone model and a simplified 3-zone model (easy, moderate, hard).

How long should I train in each zone?

A common approach is about 80% easy and 20% harder work. Beginners should start mostly in Zones 1–2 and add harder sessions gradually.

Can I train by heart rate without a monitor?

Yes. Use the 10-second pulse count, or the talk test: Zone 2 lets you speak in full sentences, Zone 4 only short phrases.

Conclusion

Heart rate zones take the guesswork out of training. Start by choosing a method: percentage of max heart rate for a quick estimate, Karvonen if you know your resting heart rate, or lactate threshold if you can do a hard 30-minute test. Then spend most of your time in the easy zones (1 and 2), add a smaller share of harder work, and use the talk test to check that the numbers match how you feel.

Remember that every formula is an estimate and your body may sit 10 bpm or more away from the chart. Recalculate your zones as your fitness improves, adjust them if your watch or monitor tells you something different, and be consistent. Use the calculator above to get your personal zones, and try the weekly planner to turn them into a simple training plan.

Medical Disclaimer

The information in this article and the heart rate zone calculator is provided for general educational and informational purposes only. It is not medical advice and is not a substitute for professional diagnosis, treatment or guidance from a qualified doctor or healthcare provider.

Heart rate zones and maximum heart rate formulas are estimates, and individual results can vary widely. Consult your doctor before starting or changing an exercise programme, especially if you have a heart condition, high blood pressure, diabetes or another medical condition, are pregnant, take medication that affects heart rate (such as beta-blockers), or have been inactive for a long time.

Stop exercising and seek immediate medical help if you experience chest pain or pressure, severe shortness of breath, dizziness, fainting or an irregular heartbeat. In an emergency, call your local emergency number.