Heart Rate Zones: How to Calculate Your 5 Zones

Heart rate zones are five intensity bands based on your maximum heart rate (HRmax). Estimate HRmax with 208 - 0.7 × age. Zone 1 is 50-60% of HRmax, zone 2 is 60-70%, zone 3 is 70-80%, zone 4 is 80-90% and zone 5 is 90-100%. For a 40-year-old, zone 2 is about 108-126 bpm.

Key takeaways

• Use the Tanaka formula, 208 - 0.7 × age, instead of 220 - age.
• The Karvonen formula adds resting heart rate, which personalizes your zones.
• Predicted HRmax can be off by 10-12 bpm, so confirm zones with the talk test.
• Most people should spend about 80% of cardio sessions in zones 1-2 and about 20% in zones 4-5.

What are the different heart rate zones?

Each zone matches a different effort level and a different training effect. The table below shows the standard 5-zone model.

• 1 Recovery: % HRmax 50-60%, Talk test Easy chatting, RPE (1-10) 1-2, What's happening Well below the first lactate threshold, Purpose Recovery, warm-up
• 2 Endurance: % HRmax 60-70%, Talk test Full sentences, RPE (1-10) 3-4, What's happening Just under the first lactate threshold, Purpose Aerobic base, mitochondria
• 3 Tempo: % HRmax 70-80%, Talk test Short sentences, RPE (1-10) 5-6, What's happening Between the two lactate thresholds, Purpose Race endurance
• 4 Threshold: % HRmax 80-90%, Talk test A few words, RPE (1-10) 7-8, What's happening Around the second lactate threshold, Purpose Raise lactate threshold
• 5 VO2 max: % HRmax 90-100%, Talk test Can't talk, RPE (1-10) 9-10, What's happening Above the second threshold, Purpose Raise VO2 max

The two lactate thresholds explain the zone borders. The first (LT1) is where lactate starts to rise, around 2 mmol/L. The second (LT2) is where it builds up fast, around 4 mmol/L. LT2 is roughly the pace you could hold for an hour.

These thresholds also map onto the three energy systems. Zones 1-2 run almost entirely on aerobic metabolism. Zones 4-5 lean more on glycolysis.

How to calculate heart rate zones

You need one number for the simple method and two for the more precise method.

Step 1: Estimate your max heart rate

• HRmax = 208 - 0.7 × age

This is the Tanaka formula. It came from a meta-analysis of 351 studies and 18,712 people. The authors found 220 - age underestimates HRmax in older adults (Tanaka et al. 2001).

Step 2a: Simple method (% of HRmax)

• Target HR = HRmax × % intensity

Step 2b: Karvonen method (heart rate reserve)

• Heart rate reserve (HRR) = HRmax - HRrest
• Target HR = HRR × % intensity + HRrest

Measure resting heart rate (HRrest) in the morning, lying down, before coffee. Average three mornings.

Karvonen accounts for fitness. A fit person with a low resting heart rate gets zones that start lower and spread wider.

Worked example

Age 40, resting heart rate 60 bpm.

• HRmax = 208 - 0.7 × 40 = 208 - 28 = 180 bpm
• HRR = 180 - 60 = 120 bpm
• 70% target (Karvonen) = 120 × 0.70 + 60 = 144 bpm
• 70% target (simple) = 180 × 0.70 = 126 bpm

Note the gap. The same "70%" gives 144 bpm with Karvonen and 126 bpm with the simple method. Pick one method and stick with it, because the zone percentages are not interchangeable. The 5-zone table above uses % of HRmax.

Heart rate zones by age

Here are the zones by % of HRmax, using the Tanaka formula. Values are rounded to the nearest beat.

• 20: Est. HRmax 194, Zone 1 (50-60%) 97-116, Zone 2 (60-70%) 116-136, Zone 3 (70-80%) 136-155, Zone 4 (80-90%) 155-175, Zone 5 (90-100%) 175-194
• 30: Est. HRmax 187, Zone 1 (50-60%) 94-112, Zone 2 (60-70%) 112-131, Zone 3 (70-80%) 131-150, Zone 4 (80-90%) 150-168, Zone 5 (90-100%) 168-187
• 40: Est. HRmax 180, Zone 1 (50-60%) 90-108, Zone 2 (60-70%) 108-126, Zone 3 (70-80%) 126-144, Zone 4 (80-90%) 144-162, Zone 5 (90-100%) 162-180
• 50: Est. HRmax 173, Zone 1 (50-60%) 87-104, Zone 2 (60-70%) 104-121, Zone 3 (70-80%) 121-138, Zone 4 (80-90%) 138-156, Zone 5 (90-100%) 156-173
• 60: Est. HRmax 166, Zone 1 (50-60%) 83-100, Zone 2 (60-70%) 100-116, Zone 3 (70-80%) 116-133, Zone 4 (80-90%) 133-149, Zone 5 (90-100%) 149-166
• 70: Est. HRmax 159, Zone 1 (50-60%) 80-95, Zone 2 (60-70%) 95-111, Zone 3 (70-80%) 111-127, Zone 4 (80-90%) 127-143, Zone 5 (90-100%) 143-159

Treat this as a starting point. Two people of the same age can have true max heart rates 20 beats apart.

What are my heart rate zones? Making them accurate

Predicted HRmax has an error of about ±10-12 bpm. If yours is far off, every zone shifts. Three ways to get closer:

• Talk test. Zone 2 should allow full sentences. If you can't, you're too high regardless of the number.
• Field test. After a thorough warm-up, do a hard 3-4 minute uphill effort and go all-out in the last 30 seconds. The highest heart rate you see is close to your HRmax. Only do this if you're healthy and used to hard exercise.
• Lab test. A graded exercise test measures HRmax directly, and often your lactate thresholds too.

Some medications change the picture. Beta-blockers blunt heart rate, so use perceived effort (RPE) instead. During pregnancy, use the talk test rather than heart rate formulas.

Cardio heart rate zones: how to use them

The zones are tools, not goals in themselves. Most of the benefit comes from how you spread your time across them.

Elite endurance athletes do about 80% of sessions in zones 1-2 and about 20% in zones 4-5 (Seiler 2010). They spend little time in zone 3. That middle zone becomes a "grey zone" when every run lands there. It's too hard to recover from quickly and too easy to drive big gains.

For general fitness, 2-3 easy sessions plus 1 hard session per week works well. Read our guide to zone 2 training for the easy days. For the hard day, try Norwegian 4x4 intervals at 90-95% of HRmax.

Running heart rate zones

The same five zones apply to running. The hard part is keeping easy runs easy. Many beginners must walk hills or alternate walking and jogging to stay in zone 2. That's normal, and it gets easier as the aerobic base improves.

Running also carries more impact than cycling or rowing. If your joints complain, do some zone 2 work on a bike or rower instead.

How to apply this

• Calculate HRmax with 208 - 0.7 × age.
• Measure resting heart rate on three mornings and average it if you want Karvonen zones.
• Write down your five zones in bpm, using one method only.
• Check them with the talk test in your first two weeks. Adjust if the numbers and feel disagree.
• Plan your week: 2-3 sessions in zone 2, 1 session in zones 4-5, little in zone 3.
• Track trends. A lower heart rate at the same pace means you're getting fitter. See how to improve your VO2 max for the next step.

FAQ

How do you calculate heart rate zones?

Estimate max heart rate with 208 - 0.7 × age. Multiply it by the zone percentages: 50-60%, 60-70%, 70-80%, 80-90% and 90-100%. For more precision, use the Karvonen formula, which adds your resting heart rate.

What are my heart rate zones if I'm 40?

Your estimated max heart rate is 180 bpm. Zone 1 is about 90-108 bpm, zone 2 is 108-126, zone 3 is 126-144, zone 4 is 144-162 and zone 5 is 162-180. Your true max may differ by 10-12 bpm, so confirm with the talk test.

Why is 208 - 0.7 × age better than 220 - age?

The Tanaka formula came from a meta-analysis of 18,712 people. Its authors found that 220 - age underestimates max heart rate in older adults. Both are still estimates, so field or lab tests are more accurate.

What is the Karvonen formula?

Karvonen calculates target heart rate as (HRmax - HRrest) × intensity + HRrest. It uses heart rate reserve, so your fitness level shapes your zones. For a 40-year-old with a resting rate of 60, 70% intensity equals 144 bpm.

Which heart rate zone is best for cardio?

No single zone is best. Most training should sit in zone 2, with about one hard session per week in zones 4-5. This 80:20 mix builds an aerobic base and raises VO2 max.

What are good running heart rate zones for beginners?

Use the same five zones, built from 208 - 0.7 × age. Most beginner runs should stay in zone 2, even if that means walking hills. Add one harder session per week once easy running feels comfortable.

Sources

• Tanaka H, Monahan KD, Seals DR. 2001. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. https://doi.org/10.1016/S0735-1097(00)01054-8
• Seiler S. 2010. What is best practice for training intensity and duration distribution in endurance athletes? Int J Sports Physiol Perform. https://doi.org/10.1123/ijspp.5.3.276
• Helgerud J et al. 2007. Aerobic high-intensity intervals improve VO2max more than moderate training. Med Sci Sports Exerc. https://doi.org/10.1249/mss.0b013e3180304570
• Bull FC et al. 2020. WHO 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med. https://doi.org/10.1136/bjsports-2020-102955
• ACSM. 2021. Guidelines for Exercise Testing and Prescription, 11th ed. Wolters Kluwer.

Want the heart rate math next to every other training formula? The Field Manual has a one-page formula sheet with Tanaka, Karvonen, METs and the Cooper test. Its knowledge checks let you practice the calculations until they're automatic.