Español
Health

Maximum Heart Rate Calculator

Calculate your maximum heart rate (MHR) and your five training zones to optimise your workout sessions.

Maximum heart rate (MHR) is the highest number of beats per minute your heart can reach during maximum exertion. It is a key metric for planning your training: knowing at what percentage of your MHR you are working in each session lets you control exercise intensity, improve performance and reduce the risk of overtraining.

This calculator uses the Tanaka formula (2001), validated in a meta-analysis of more than 18,000 people and considered more accurate than the classic '220 − age' formula. From your MHR it automatically calculates your five training zones, each with different physiological goals: from active recovery to maximum effort.

Your age

Max Heart Rate (MHR)

187 bpm

Beats per minute using the Tanaka formula (208 − 0.7 × age)

Training zones

Zone 1 — Recovery

Warm-up and active recovery

94–112

50–60%

Zone 2 — Base aerobic

Fat burning and aerobic endurance

112–131

60–70%

Zone 3 — Upper aerobic

Cardiovascular improvement

131–150

70–80%

Zone 4 — Anaerobic

Anaerobic threshold and power

150–168

80–90%

Zone 5 — Maximum

Maximum effort (short sprints)

168–187

90–100%

Results are indicative only. Consult a doctor or sports professional before starting high-intensity training programmes.

How your training zones are calculated

The process has two steps. First, maximum heart rate is estimated with Tanaka's formula: MHR = 208 − 0.7 × age. This equation replaced the classic '220 − age' because the latter underestimated MHR in older people and overestimated it in younger ones. Then the percentages that define each zone are applied to that MHR: Zone 1 runs from 50 to 60%, Zone 2 from 60 to 70%, Zone 3 from 70 to 80%, Zone 4 from 80 to 90% and Zone 5 above 90%. Each band corresponds to an intensity and produces different physiological adaptations.

Worked example

For a 35-year-old: MHR = 208 − 0.7 × 35 = 208 − 24.5 = 183.5 bpm, which we round to 184 bpm. From there, Zone 2 (60-70%) falls between 110 and 129 bpm, ideal for long easy runs and fat burning; Zone 4 (80-90%), which trains the lactate threshold, sits between 147 and 165 bpm; and Zone 5 starts at 165 bpm. With the old '220 − age' formula this same person would have got 185 bpm, a small difference at this age but one that widens considerably beyond 50.

Training zones and what they are for

Zone% MHRMain purpose
Zone 1 — Recovery50–60 %Warm-up and active recovery
Zone 2 — Base aerobic60–70 %Fat burning and aerobic endurance
Zone 3 — Upper aerobic70–80 %Cardiovascular improvement
Zone 4 — Anaerobic80–90 %Anaerobic threshold and power
Zone 5 — Maximum90–100 %Maximum effort (short sprints)

How to interpret the result

Use the zones as an intensity guide, not a rigid boundary. A common beginner mistake is always training in Zone 3, too hard to build volume and too easy to improve the threshold: the so-called 'grey zone'. Endurance athletes follow the opposite distribution, spending around 80% of their time in Zones 1 and 2 and only 20% in Zones 4 and 5. Bear in mind too that heart rate responds to effort with a lag and is affected by heat, dehydration, stress, caffeine or lack of sleep, so in some sessions your readings will not faithfully reflect the actual intensity of the exercise.

Frequently asked questions

The most widely used formula is Tanaka's (2001): MHR = 208 − 0.7 × age. It is more accurate than the classic '220 − age' formula because it was validated in a meta-analysis of more than 18,000 people. MHR is individual and can vary ±10-12 bpm between people of the same age; the only way to measure it accurately is through a maximal exercise stress test supervised by a sports medicine doctor.

Each heart rate zone produces different physiological adaptations. Zone 2 (60-70%) is ideal for improving base aerobic capacity and burning fat as the primary fuel; endurance runners spend up to 80% of their training volume here. Zone 4 (80-90%) trains the lactate threshold and improves performance in sustained efforts of 20-60 minutes. Zone 5 (>90%) develops maximum power and VO₂max, but cannot be sustained for more than a few minutes.

For healthy people with no cardiovascular risk factors, occasionally training in Zone 4 or 5 is safe if a solid aerobic base (Zones 1-3) has been built beforehand. However, if you are over 40, have been sedentary for a long time, or have a history of heart disease, consult your doctor before high-intensity training. As a general rule, never exceed 85% of your MHR without medical supervision if you are a beginner.

It is the number of beats per minute when you are completely relaxed, ideally measured in the morning before getting out of bed. In a healthy adult it usually sits between 60 and 100 bpm, though trained people can drop below 50 and even to 40 bpm in elite endurance athletes, because the heart pumps more blood with each beat. A resting rate that falls over the weeks is a good sign that your fitness is improving. Conversely, if it is elevated for several days in a row it may indicate accumulated fatigue, lack of sleep, dehydration or the onset of an infection.

Because the formulas are statistical estimates and your physiology is individual. Real MHR can deviate ±10-12 bpm from the calculated value among people of the same age, so your actual zones could be shifted. Technology also matters: optical wrist sensors are less accurate than chest straps, especially during intense efforts or with sharp arm movements. If you train by zones seriously, the recommendation is to do a stress test or a supervised field test to determine your real MHR and threshold rather than relying on the formula alone.

Other Health calculators

BMICalculate your Body Mass Index and find your weight category.
Calories & BMRCalculate your BMR and daily calorie needs by activity and goal.
Daily WaterFind out how much water you should drink per day based on your weight and activity.
See all