Heart Rate Zone Calculator
A 40-year-old has an estimated maximum heart rate of 180 bpm, which puts Zone 2 at about 108 to 126 bpm and Zone 4 at about 144 to 162 bpm. This heart rate zone calculator estimates training zones from the common 220 minus age method, then shows each zone as a heart rate range in beats per minute. If you also know your resting heart rate, the tool adds heart rate reserve zones, which shift the ranges upward to reflect the gap between your resting pulse and your estimated maximum. That makes the page useful for runners, cyclists, walking programs, interval training, spin classes, and general cardio plans where you want a practical target instead of a raw percentage. The numbers here are estimates, not exact prescriptions. Two people of the same age can have very different true maximum heart rates, different resting heart rates, and very different responses to heat, stress, medication, fitness level, and fatigue. Use the results as a starting point for pacing an easy day, a steady aerobic session, or a harder interval block, then compare the estimate with how the effort feels and any guidance you have from a coach or healthcare professional.
Quick answer
The calculator estimates maximum heart rate with 220 minus age, then multiplies that result by standard zone percentages from 50% to 100%.
What this tells you
- •The calculator estimates maximum heart rate with 220 minus age, then multiplies that result by standard zone percentages from 50% to 100%.
- •Zone 1 and Zone 2 usually describe easier aerobic work, while Zone 4 and Zone 5 represent much harder efforts that are harder to hold for long.
- •If you enter resting heart rate, the tool also shows heart rate reserve zones using the Karvonen-style method of adding a percentage of your reserve back to your resting pulse.
- •Heart rate reserve often gives higher zone numbers than the plain percent-of-max method because it reflects where your heart rate starts at rest instead of assuming everyone starts from zero.
- •These ranges help with training structure, but they do not diagnose fitness, heart health, or exercise safety.
- •A chest strap or well-fitted wearable can help you compare your live exercise heart rate with the estimated ranges shown here.
How to Use
- 11. Enter your age in years. The tool needs age because it estimates maximum heart rate as 220 minus age.
- 22. Enter your resting heart rate if you know it from a calm morning reading or a reliable device trend. Leave it blank if you only want the standard percent-of-max zones.
- 33. Click Calculate to see your estimated maximum heart rate plus five training zones from 50% to 100% intensity.
- 44. Read the percent-of-max zones first if you want a simple starting point. Read the heart rate reserve zones as well if you use resting pulse in your training plan.
- 55. Match the zone to the workout goal. Easier recovery and long steady sessions usually sit in lower zones, while tempo work, hills, and short intervals often push into higher zones.
- 66. Use the result as a planning range, then adjust for real-world factors like heat, sleep loss, dehydration, medication effects, and how hard the effort actually feels.
How It Works
Formula
Estimated Max HR = 220 - Age
Zone Range = Estimated Max HR × Zone %
Heart Rate Reserve = Estimated Max HR - Resting HR
HRR Zone Range = (Heart Rate Reserve × Zone %) + Resting HRThe first step is estimating maximum heart rate from age. If you are 40, the estimate is 220 - 40 = 180 bpm. The basic zone method then multiplies that 180 bpm by each zone band. Zone 1 uses 50% to 60%, so the range becomes 90 to 108 bpm. Zone 4 uses 80% to 90%, so the range becomes 144 to 162 bpm. When resting heart rate is available, the tool calculates heart rate reserve as estimated max heart rate minus resting heart rate. It then multiplies that reserve by each zone percentage and adds resting heart rate back in. For example, if age is 30 and resting heart rate is 60 bpm, estimated max heart rate is 190 bpm and reserve is 130 bpm. A 60% to 70% reserve-based zone becomes (130 × 0.60) + 60 = 138 bpm to (130 × 0.70) + 60 = 151 bpm. The tool rounds each zone boundary to the nearest whole beat because that matches how most people use training targets during exercise.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Age 40 with percent-of-max zones only
The formula starts with 220 - 40 = 180 bpm for estimated maximum heart rate. Zone 2 is 60% to 70% of 180, which gives 108 to 126 bpm. Zone 4 is 80% to 90% of 180, which gives 144 to 162 bpm. This is a useful example when you want simple training ranges without using resting pulse.
Age 30 with resting heart rate of 60 bpm
Estimated maximum heart rate is 220 - 30 = 190 bpm. Using the basic method, Zone 2 is 190 × 0.60 to 190 × 0.70, which rounds to 114 to 133 bpm. Heart rate reserve is 190 - 60 = 130 bpm. Using the reserve method, Zone 2 becomes (130 × 0.60) + 60 = 138 bpm up to (130 × 0.70) + 60 = 151 bpm. This shows why reserve-based zones usually sit higher than plain percent-of-max zones for the same person.
Age 50 with resting heart rate of 70 bpm
For age 50, estimated maximum heart rate is 220 - 50 = 170 bpm. Zone 1 by max uses 50% to 60%, so 170 × 0.50 = 85 bpm and 170 × 0.60 = 102 bpm. Heart rate reserve is 170 - 70 = 100 bpm. Zone 1 by reserve becomes (100 × 0.50) + 70 = 120 bpm to (100 × 0.60) + 70 = 130 bpm. A person using reserve-based training would aim much higher than the plain max-percent method for the same easy session.
Age 60 with resting heart rate of 60 bpm
The age-based estimate is 220 - 60 = 160 bpm. Zone 3 by max is 70% to 80% of 160, which gives 112 to 128 bpm. Heart rate reserve is 160 - 60 = 100 bpm. Zone 3 by reserve becomes (100 × 0.70) + 60 = 130 bpm to (100 × 0.80) + 60 = 140 bpm. This example is helpful if you want to compare moderate steady work under both methods before choosing a training approach.
Age 20 with resting heart rate of 60 bpm
At age 20, the estimate is 220 - 20 = 200 bpm. Zone 5 by max uses 90% to 100%, so the range is 180 to 200 bpm. Heart rate reserve is 200 - 60 = 140 bpm. Zone 5 by reserve becomes (140 × 0.90) + 60 = 186 bpm up to (140 × 1.00) + 60 = 200 bpm. This illustrates how the two methods get closer together near the top end because both approaches still finish at the same estimated maximum heart rate.
Priya, age 45, resting pulse 58, planning an easy long run
Priya wants her Sunday long run to stay conversational. The tool estimates her maximum at 220 - 45 = 175 bpm, so Zone 2 by the plain percent-of-max method is 175 × 0.60 = 105 bpm to 175 × 0.70 = 122.5 bpm, shown as 105 to 122 after rounding. Her resting pulse of 58 gives a reserve of 175 - 58 = 117 bpm. Zone 2 by reserve is (117 × 0.60) + 58 = 128.2 bpm to (117 × 0.70) + 58 = 139.9 bpm, shown as 128 to 140. The two methods disagree by about 20 bpm for the same easy run, which is normal for someone with a low resting pulse. She picks the reserve range, then checks it against the talk test on the run. If she can still speak in full sentences at 138 bpm, the range is doing its job.
Heart rate zones by age using 220 minus age
Each row is the tool's percent-of-max output for that age with no resting heart rate entered. Ranges are in beats per minute and rounded to the whole beat exactly as the calculator rounds them.
| Age | Est. max HR | Zone 1 (50-60%) | Zone 2 (60-70%) | Zone 3 (70-80%) | Zone 4 (80-90%) | Zone 5 (90-100%) |
|---|---|---|---|---|---|---|
| 20 | 200 | 100 to 120 | 120 to 140 | 140 to 160 | 160 to 180 | 180 to 200 |
| 25 | 195 | 98 to 117 | 117 to 137 | 137 to 156 | 156 to 176 | 176 to 195 |
| 30 | 190 | 95 to 114 | 114 to 133 | 133 to 152 | 152 to 171 | 171 to 190 |
| 35 | 185 | 93 to 111 | 111 to 130 | 130 to 148 | 148 to 167 | 167 to 185 |
| 40 | 180 | 90 to 108 | 108 to 126 | 126 to 144 | 144 to 162 | 162 to 180 |
| 45 | 175 | 88 to 105 | 105 to 122 | 122 to 140 | 140 to 158 | 158 to 175 |
| 50 | 170 | 85 to 102 | 102 to 119 | 119 to 136 | 136 to 153 | 153 to 170 |
| 55 | 165 | 83 to 99 | 99 to 115 | 115 to 132 | 132 to 149 | 149 to 165 |
| 60 | 160 | 80 to 96 | 96 to 112 | 112 to 128 | 128 to 144 | 144 to 160 |
| 65 | 155 | 78 to 93 | 93 to 109 | 109 to 124 | 124 to 140 | 140 to 155 |
| 70 | 150 | 75 to 90 | 90 to 105 | 105 to 120 | 120 to 135 | 135 to 150 |
Computed with the formula above: estimated max HR = 220 - age, zone boundary = max HR × band percent, rounded to the nearest beat. Enter a resting heart rate on the form to see the reserve-based ranges, which sit higher. The 220 minus age rule comes from Fox, Naughton and Haskell 1971. Tanaka, Monahan and Seals 2001 (208 - 0.7 × age) and Gellish et al. 2007 (207 - 0.7 × age) give higher maximums after about age 40, as the explainer below shows.
Where 220 minus age comes from and how far it can be off
The 220 minus age rule was never derived as a regression. Fox, Naughton and Haskell published it in a 1971 review in Annals of Clinical Research as a rough line through a handful of earlier studies, and it stuck because it is easy to remember. Larger studies since then have measured something flatter. Tanaka, Monahan and Seals pooled 351 studies covering 18,712 people in the Journal of the American College of Cardiology in 2001 and found maximal heart rate = 208 - 0.7 × age, independent of sex and fitness level. Gellish and colleagues followed 132 people for up to 25 years and reported 207 - 0.7 × age in Medicine and Science in Sports and Exercise in 2007. All three formulas agree near age 40. At 20 they give 200, 194 and 193 bpm. At 45 they give 175, 176.5 and 175.5. At 70 they give 150, 159 and 158, so this tool's estimate, and every zone built on it, runs about 8 to 9 bpm low for people in their late sixties and seventies.
Even the better formulas carry wide error bars. The Tanaka meta-analysis reported a standard deviation of roughly 10 bpm around its line, which means about one adult in three has a true maximum more than 10 bpm away from any age-based estimate, and a 40-year-old whose formula value is 180 could realistically max out anywhere from the high 160s to the low 190s. That is why the ranges on this page are a starting point for structuring sessions, not a measurement. A graded exercise test, or a well-executed maximal field effort with a chest strap, replaces the estimate with a personal number.
The two zone methods answer different questions. Percent of max simply scales the estimated ceiling. The reserve method, usually credited to Karvonen, Kentala and Mustala's 1957 training study in Annales Medicinae Experimentalis et Biologiae Fenniae, measures intensity as a fraction of the gap between resting and maximal heart rate and adds the resting pulse back. The American College of Sports Medicine uses heart rate reserve in its exercise prescription guidance because a given percentage of reserve tracks the matching percentage of oxygen uptake reserve more closely than percent of max does. In the ACSM position stand by Garber and colleagues in 2011, moderate intensity is defined as 40 to 59 percent of heart rate reserve and vigorous as 60 percent and above. By that definition, this tool's Zone 1 by reserve is light to moderate, Zone 2 by reserve is already vigorous, and the five equal 10 percent bands on this page are a common consumer convention rather than an ACSM classification. Zone labels on watches and in training plans differ for the same reason, so compare the percentages behind a label before assuming two sets of numbers disagree.
Plenty of everyday things pull real exercise heart rate away from any formula. Beta blockers and some other medications lower both resting and maximal heart rate, which breaks the age estimate entirely. Heat, dehydration, altitude, caffeine, illness and poor sleep raise heart rate at a given pace, so a Zone 2 ceiling reached on a hot day reflects less work than the same number on a cool one. Wrist optical sensors can lag or lock onto cadence during intervals and arm-heavy movement. Anyone with heart disease, chest pain, fainting or unexplained breathlessness during exercise should get intensity targets from a clinician rather than from an age formula. Used with those caveats, the table above is a reasonable first guess that effort, breathing and a chest strap can refine within a few sessions.
Common mistakes
- Using the zone estimate as if it were a lab-tested personal maximum heart rate. The 220 minus age method is common, but your real number may be noticeably higher or lower.
- Entering a casual daytime pulse as resting heart rate. Heart rate reserve works best when the resting value comes from a calm, consistent measurement rather than after coffee, stress, or movement.
- Comparing percent-of-max zones with reserve-based zones without noticing that they are different methods. The ranges can differ by a lot even when the age and workout goal stay the same.
- Treating one zone as the best zone for every goal. Easy mileage, recovery work, threshold training, and short interval work usually need different intensities.
- Ignoring symptoms, medications, or medical restrictions because the numbers look reasonable. A training estimate should never overrule personal clinical guidance.
Limitations
This tool uses a population-level age formula and fixed zone bands. The 220 minus age rule comes from a 1971 review by Fox, Naughton and Haskell and was not fitted to a dataset. Tanaka, Monahan and Seals 2001 (208 - 0.7 × age) and Gellish et al. 2007 (207 - 0.7 × age) give maximums about 8 to 9 bpm higher at age 70, and even those formulas carry a standard deviation near 10 bpm, so your true maximum can sit well outside any estimate. The five equal 10 percent bands are a consumer convention, not the ACSM intensity classification, which defines moderate exercise as 40 to 59 percent of heart rate reserve and vigorous as 60 percent and above (Garber et al. 2011). The tool cannot measure your true maximum heart rate, lactate threshold, or personal response to exercise, and it does not adjust for beta blockers or other medications, heat, altitude, dehydration, illness, stress, caffeine, or recent fatigue. Wrist wearables can also misread exercise pulse, especially during intervals or arm-heavy movement. Use the ranges as a starting estimate for training structure, not as a precise performance test.
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