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Formula
Max HR = 220 − age, or 208 − 0.7 × age; zone heart rate = max HR × intensity, or with resting HR (Karvonen) = (max HR − resting HR) × intensity + resting HR
- Max HR
- estimated maximum heart rate in beats per minute (bpm)
- age
- your age in whole years
- intensity
- the zone boundary as a decimal: 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0
- resting HR
- your heart rate at rest, best measured on waking
What the heart rate zone calculator gives you
Training by heart rate is a simple way to control how hard you work. This heart rate zone calculator turns your age, and optionally your resting pulse, into:
- Estimated maximum heart rate, by 220 − age or by Tanaka’s 208 − 0.7 × age.
- A five-zone table in beats per minute, from very light to maximum effort.
- Zone 2, the easy endurance range, called out on its own.
- Moderate and vigorous ranges as defined by the American Heart Association.
If you enter a resting heart rate, the zones switch to the Karvonen method, also called the heart rate reserve method.
How to use the heart rate zone calculator
- Enter your age in whole years.
- Choose the max heart rate formula. 220 − age is the classic; Tanaka is the newer, research-based choice and fits older adults better.
- Optionally add your resting heart rate. Count your pulse for a full minute after waking, before you get up, on two or three mornings and use the average.
- Read your zones from the table and set them in your watch or bike computer.
The five heart rate zones
| Zone | Intensity | How it feels | Typical use |
|---|---|---|---|
| 1 · Very light | 50–60% | Easy walking pace | Warm-up, recovery days |
| 2 · Light | 60–70% | Comfortable, can talk in full sentences | Long, easy endurance sessions |
| 3 · Moderate | 70–80% | Breathing harder, short sentences | Steady aerobic work |
| 4 · Hard | 80–90% | Can say only a few words | Tempo and threshold training |
| 5 · Maximum | 90–100% | Cannot keep it up for long | Short intervals and sprints |
Zones 1 and 2 together match the American Heart Association’s moderate range (50–70%), and zone 3 plus the lower half of zone 4 match its vigorous range (70–85%).
How the calculation works
Maximum heart rate
The classic formula, 220 − age, gives 180 bpm at 40. Tanaka, Monahan and Seals pooled 351 studies with nearly 19,000 people and found 208 − 0.7 × age a better fit, especially for older adults. The two formulas agree at age 40 and drift apart at both ends.
| Age | 220 − age | 208 − 0.7 × age | Difference |
|---|---|---|---|
| 20 | 200 bpm | 194 bpm | −6 |
| 30 | 190 bpm | 187 bpm | −3 |
| 40 | 180 bpm | 180 bpm | 0 |
| 50 | 170 bpm | 173 bpm | +3 |
| 60 | 160 bpm | 166 bpm | +6 |
| 70 | 150 bpm | 159 bpm | +9 |
Percent of maximum vs. Karvonen
With % of maximum, each zone is simply max HR × percentage. The Karvonen method first subtracts your resting heart rate to get the heart rate reserve, takes the percentage of that, and adds the resting rate back. For someone with a low resting pulse this gives noticeably higher numbers in the easy zones, which usually matches how the effort feels.
Calculating heart rate zones by hand (Karvonen)
Take a 45-year-old using the Tanaka formula with a resting heart rate of 60 bpm.
- Max HR = 208 − 0.7 × 45 = 208 − 31.5 = 176.5 bpm, about 177.
- Heart rate reserve = 176.5 − 60 = 116.5 bpm.
- Zone 3 low end: 116.5 × 0.7 + 60 = 141.55, about 142 bpm.
- Zone 3 high end: 116.5 × 0.8 + 60 = 153.2, about 153 bpm.
Without the resting heart rate, zone 3 would be 176.5 × 0.7 ≈ 124 to 176.5 × 0.8 ≈ 141 bpm, almost 20 beats lower at the bottom.
| Zone | % of max (max 177) | Karvonen (rest 60) |
|---|---|---|
| 1 · Very light | 88–106 bpm | 118–130 bpm |
| 2 · Light | 106–124 bpm | 130–142 bpm |
| 3 · Moderate | 124–141 bpm | 142–153 bpm |
| 4 · Hard | 141–159 bpm | 153–165 bpm |
| 5 · Maximum | 159–177 bpm | 165–177 bpm |
Putting your zones to use
- Building endurance. Most endurance plans put the bulk of weekly training in zones 1 and 2, with a smaller share of hard work in zones 4 and 5.
- Meeting activity guidelines. Time spent in the AHA moderate or vigorous range counts toward the weekly 150 minutes of moderate or 75 minutes of vigorous activity.
- Pacing runs and rides. Pair your zones with the pace calculator to see which paces keep you in zone 2.
- Estimating energy use. Harder zones burn more calories per minute; the calories burned calculator estimates the total for an activity.
Common mistakes
- Treating any heart rate zone calculator as exact. Two people of the same age can have maximum heart rates 20 bpm apart. If your zones feel wrong, trust how hard the effort feels and adjust.
- Measuring resting heart rate after coffee or exercise. Both raise it. Measure in the morning before getting up.
- Ignoring heart rate lag. Heart rate takes a minute or two to settle after you change pace, so short intervals rarely reach their target zone.
- Training through medication effects. Beta blockers flatten heart rate response. Use perceived effort and ask your doctor for targets.
- Pushing into zone 5 without a base. If you are new to exercise or have a heart condition, build up gradually and talk to a doctor before high-intensity work.
Glossary
- Maximum heart rate (max HR). The highest heart rate you can reach during all-out effort.
- Resting heart rate. Beats per minute when fully at rest, ideally measured on waking.
- Heart rate reserve (HRR). Maximum heart rate minus resting heart rate.
- Karvonen method. Setting training zones as a percentage of heart rate reserve plus resting heart rate.
Worked examples
Age 35, 220 − age, no resting heart rate
A 35-year-old using the classic 220 − age estimate, with zones as a percentage of max heart rate.
Inputs: Age = 35 years; Max heart rate formula = 220 − age (Fox)
Max HR: 220 − 35 = 185 bpm Zone 2 low end: 185 × 0.6 = 111 bpm
Answer: Age 35: estimated max heart rate 185 bpm; zone 2 is 111–130 bpm (% of max HR). An estimate, not medical advice.
Age 52, Tanaka formula with resting heart rate
A 52-year-old using 208 − 0.7 × age and a resting pulse of 58 bpm, so zones use the Karvonen method.
Inputs: Age = 52 years; Max heart rate formula = 208 − 0.7 × age (Tanaka); Resting heart rate (optional) = 58 bpm
Max HR: 208 − 0.7 × 52 = 171.6 bpm Heart rate reserve: 171.6 − 58 = 113.6 bpm Zone 2 low end: 113.6 × 0.6 + 58 = 126.2 ≈ 126 bpm
Answer: Age 52: estimated max heart rate 172 bpm; zone 2 is 126–138 bpm (Karvonen). An estimate, not medical advice.
Age 68 with a high resting heart rate (edge case)
A 68-year-old with a resting pulse of 104 bpm, above the usual adult range, which triggers a note.
Inputs: Age = 68 years; Max heart rate formula = 208 − 0.7 × age (Tanaka); Resting heart rate (optional) = 104 bpm
Max HR: 208 − 0.7 × 68 = 160.4 bpm Heart rate reserve: 160.4 − 104 = 56.4 bpm Zone 2 low end: 56.4 × 0.6 + 104 = 137.8 ≈ 138 bpm
Answer: Age 68: estimated max heart rate 160 bpm; zone 2 is 138–143 bpm (Karvonen). An estimate, not medical advice.
Assumptions and limitations
- This is an estimate, not medical advice. Age-based formulas predict maximum heart rate with a typical error of about 10 bpm either way, so your real zones may be higher or lower. A supervised exercise test measures your maximum directly.
- Zones use a common five-zone model at 50–60%, 60–70%, 70–80%, 80–90% and 90–100% intensity. Zone names and uses are general training conventions, not clinical categories.
- Without a resting heart rate, zones are a percentage of maximum heart rate. With one, they are a percentage of heart rate reserve (Karvonen), which gives higher numbers in the lower zones.
- Heart rates are rounded to the nearest whole beat; adjacent zones share their boundary value.
- Beta blockers and some other medicines lower heart rate and make age-based zones unreliable. If you take them, have a heart condition, or are starting exercise after a long break, check with your doctor first.
- A resting heart rate above 100 bpm or below 40 bpm triggers a note suggesting you check it with a doctor.
Frequently asked questions
How do you calculate heart rate zones?
Estimate your maximum heart rate, for example 220 − age, then multiply it by each zone's percentages. At age 40 the maximum is 180 bpm, so zone 2 (60–70%) is 108 to 126 bpm. With a resting heart rate, subtract it from the maximum first, take the percentage of that reserve, and add the resting rate back.
How do you calculate heart rate zone 2?
Zone 2 is 60–70% of your maximum heart rate, or of your heart rate reserve if you use the Karvonen method. It feels easy enough to hold a conversation and is used for long, steady endurance work.
Which max heart rate formula should I use?
220 − age is the most widely known. Tanaka's 208 − 0.7 × age came from a meta-analysis of 351 studies and fits older adults better. The two agree at age 40; below that, Tanaka gives slightly lower numbers, and above it slightly higher ones.
Why does adding my resting heart rate change the zones?
The Karvonen method works on the range between your resting and maximum heart rate rather than on the maximum alone. That lifts the lower zones, which better reflects effort for fit people with a low resting pulse. The top of zone 5 is the same with either method.
What is a normal resting heart rate?
For most adults, 60 to 100 beats per minute. Well-trained athletes can sit between 40 and 60. A resting rate that is often above 100, or below 60 with dizziness or fainting, is worth discussing with a doctor.
What heart rate counts as moderate or vigorous exercise?
The American Heart Association puts moderate intensity at about 50–70% of maximum heart rate and vigorous intensity at about 70–85%. The calculator shows both ranges for your age next to the five zones.
Can my real maximum heart rate be higher than the formula?
Yes. People of the same age can differ by 20 bpm or more. If you regularly see heart rates above your estimated maximum during hard efforts without symptoms, your real maximum is probably higher, and your zones shift up with it.
Sources
- Target Heart Rates Chart — American Heart Association. Checked October 10, 2026.
- Age-predicted maximal heart rate revisited — Journal of the American College of Cardiology (Tanaka, Monahan & Seals, 2001), via PubMed. Checked October 10, 2026.
- The effects of training on heart rate; a longitudinal study — Annales Medicinae Experimentalis et Biologiae Fenniae (Karvonen, Kentala & Mustala, 1957), via PubMed. Checked October 10, 2026.
- Pulse: MedlinePlus Medical Encyclopedia — US National Library of Medicine (NIH). Checked October 10, 2026.