Tool · Physiology
Max heart rate and heart-rate zones calculator
Estimate your max heart rate from your age (Tanaka formula, compared with 220 - age and Gellish) or enter your measured max HR, then get your 5 heart-rate zones in beats per minute, calculated on your heart-rate reserve (Karvonen method): the same zones as in RunMorph.
| Heart-rate zone | % HR reserve | ≈ % max HR | Range (bpm) |
|---|---|---|---|
| Z1 · Recovery | 50 to 60% | 66 to 73% | 122 to 134 bpm |
| Z2 · Easy endurance | 60 to 70% | 73 to 80% | 134 to 147 bpm |
| Z3 · Tempo | 70 to 80% | 80 to 86% | 147 to 159 bpm |
| Z4 · Threshold | 80 to 90% | 86 to 93% | 159 to 172 bpm |
| Z5 · MAS / VO₂max | 90 to 100% | 93 to 100% | 172 to 184 bpm |
Zones calculated with the Karvonen method: target HR = resting HR + % × heart-rate reserve. They take your resting heart rate into account, so they match how efforts feel better than simple percentages of max HR (the “≈ % max HR” column gives the equivalent for your values). Max HR varies by about 10 to 12 bpm between people of the same age: a measured value (supervised field test, all-out race finish) remains more accurate.
How to calculate your max heart rate
Your maximum heart rate (max HR) is the highest number of beats per minute your heart can reach during an all-out effort. It depends mostly on age (it drops over the years) and much less on fitness. Without a stress test, it’s estimated with age-based formulas.
1. The three estimation formulas
This calculator shows the three most widely used equations:
Tanaka: max HR = 208 - 0.7 × age
Gellish: max HR = 207 - 0.7 × age
Example at age 35: 220 - 35 = 185 bpm; Tanaka gives 208 - (0.7 × 35) = 208 - 24.5 ≈ 184 bpm; Gellish gives 207 - (0.7 × 35) = 207 - 24.5 ≈ 183 bpm. The three are close around your thirties; the gap widens at the extremes, where Tanaka and Gellish are considered more reliable. The calculator uses Tanaka, unless you enter your measured max HR.
2. The 5 heart-rate zones (Karvonen method)
Zones are calculated on your heart-rate reserve, the gap between your max HR and your resting heart rate. Each zone is a percentage range of that reserve: Z1 50 to 60% (recovery), Z2 60 to 70% (easy endurance), Z3 70 to 80% (tempo), Z4 80 to 90% (threshold), Z5 90 to 100% (MAS / VO₂max).
Example for a max HR of 184 bpm and a resting HR of 60 bpm: the reserve is 184 - 60 = 124 bpm. The bottom of Z2 (60%) is 60 + (0.60 × 124) ≈ 134 bpm and the top (70%) is 60 + (0.70 × 124) ≈ 147 bpm. Your easy endurance running happens between about 134 and 147 bpm.
3. What about percentages of max HR?
Many watches show zones as a simple percentage of max HR. The 60, 70, 80 and 90% reserve thresholds match, for a max HR of 190 bpm and a resting HR of 55 bpm, about 72, 79, 86 and 93% of max HR: Karvonen zones sit higher than a 60/70/80/90% split of max HR. The calculator gives the equivalent for your own values.
Chart: max HR and zones by age
Max HR estimated with the Tanaka formula (208 - 0.7 × age), then the heart-rate zones in beats per minute, calculated with the Karvonen method and a resting heart rate of 55 bpm.
| Age | Max HR | Z2 easy | Z3 tempo | Z4 threshold | Z5 MAS |
|---|---|---|---|---|---|
| 20 | 194 bpm | 138-152 bpm | 152-166 bpm | 166-180 bpm | 180-194 bpm |
| 25 | 191 bpm | 137-150 bpm | 150-164 bpm | 164-177 bpm | 177-191 bpm |
| 30 | 187 bpm | 134-147 bpm | 147-161 bpm | 161-174 bpm | 174-187 bpm |
| 35 | 184 bpm | 132-145 bpm | 145-158 bpm | 158-171 bpm | 171-184 bpm |
| 40 | 180 bpm | 130-143 bpm | 143-155 bpm | 155-168 bpm | 168-180 bpm |
| 45 | 177 bpm | 128-140 bpm | 140-153 bpm | 153-165 bpm | 165-177 bpm |
| 50 | 173 bpm | 126-138 bpm | 138-149 bpm | 149-161 bpm | 161-173 bpm |
| 55 | 170 bpm | 124-136 bpm | 136-147 bpm | 147-159 bpm | 159-170 bpm |
| 60 | 166 bpm | 122-133 bpm | 133-144 bpm | 144-155 bpm | 155-166 bpm |
These values are benchmarks for a resting heart rate of 55 bpm. The calculator above adjusts your 5 zones to your resting heart rate, and to your measured max HR if you know it.
Frequently asked questions
How do I calculate my maximum heart rate?
The most accurate way is to measure it: a supervised field test (all-out hill repeats) or the all-out finish of a short race with a chest strap. Without a measurement, it’s estimated from your age. Three formulas are common: the popular 220 - age (credited to Fox and Haskell); Tanaka, max HR = 208 - 0.7 × age; and Gellish, max HR = 207 - 0.7 × age. This calculator shows all three and uses Tanaka, the most accurate across a broad population and the one RunMorph uses. If you enter your measured max HR, it replaces the estimate.
Which max HR formula is most reliable: 220 - age or Tanaka?
The famous 220 - age formula is handy but often overestimates max HR in younger people and underestimates it in people over 40. The more recent Tanaka (208 - 0.7 × age) and Gellish (207 - 0.7 × age) equations are better calibrated on average. No formula replaces a real measurement during exercise, though: at the same age, max HR varies by about 10 to 12 bpm from one person to the next.
What are the 5 heart-rate zones for?
Heart-rate zones split effort by intensity, from Z1 (recovery) to Z5 (MAS / VO₂max), as a percentage of your heart-rate reserve: Z1 50-60%, Z2 60-70%, Z3 70-80%, Z4 80-90%, Z5 90-100%. They let you steer your training by heart rate: most of your volume goes into Z1 and Z2 (endurance), and Z3 to Z5 are saved for quality sessions. Each heart-rate zone matches the pace zone with the same number.
What is the Karvonen method?
The Karvonen method calculates zones from your heart-rate reserve, the gap between your max HR and your resting HR: target HR = resting HR + % × (max HR - resting HR). It’s more personal than a simple percentage of max HR because it reflects your fitness (a low resting heart rate points to a trained heart). It’s the method RunMorph uses. Without a resting heart rate entered, the calculator uses 55 bpm.
How do I measure my resting heart rate?
Measure it on waking, lying down, before getting up, over 60 seconds (or take the lowest value shown by a chest strap or heart-rate watch over several mornings). An adult resting heart rate is often between 50 and 70 bpm; it drops with endurance training. Avoid measuring it after coffee, exercise or a short night, which all push it up.
Turn your heart-rate zones into a training plan
RunMorph sets your sessions on your zones and builds a progressive plan, week by week, all the way to race day.
Create my free planFree · No credit card · First 3 weeks included