Tool · Physiology

Max heart rate and heart-rate zones calculator

Estimate your max heart rate from your age with three reference formulas (classic, Tanaka, Gellish), then get your 5 heart-rate zones in beats per minute. If you know your resting heart rate, switch to Karvonen mode for personalized zones, the ones that drive RunMorph sessions.

in years
in bpm, measured on waking: unlocks the Karvonen method
Your estimated max HR (Tanaka formula)
184bpm
185 bpm
Classic (220 - age)
184 bpm
Tanaka (208 - 0.7 × age)
183 bpm
Gellish (207 - 0.7 × age)
60 bpm
Resting HR
124 bpm
Heart-rate reserve (max - resting)
Zone% HR reserveRange (bpm)
Z1 · Recovery50 to 60%122 to 134 bpm
Z2 · Easy endurance60 to 70%134 to 147 bpm
Z3 · Steady endurance70 to 80%147 to 159 bpm
Z4 · Threshold80 to 90%159 to 172 bpm
Z5 · VO₂max90 to 100%172 to 184 bpm

Zones calculated with the Karvonen method, from your heart-rate reserve: they take your resting heart rate into account, so they match how efforts feel better than simple percentages of max HR. These values are estimates: max HR varies by about 10 to 12 bpm between people of the same age. A supervised field test 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:

Classic: max HR = 220 - age
Tanaka: max HR = 208 - 0.7 × age
Gellish: max HR = 207 - 0.7 × age

Example at age 35: the classic formula gives 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 as the reference for your zones.

2. The 5 heart-rate zones as % of max HR

Intensity is then split into five zones, each defined by a percentage range of max HR: Z1 50 to 60% (recovery), Z2 60 to 70% (easy endurance), Z3 70 to 80% (steady endurance), Z4 80 to 90% (threshold), Z5 90 to 100% (VO₂max).

Zone boundary (bpm) = percentage × max HR

Example for a max HR of 184 bpm: the bottom of Z2 is 0.60 × 184 ≈ 110 bpm and the top 0.70 × 184 ≈ 129 bpm. Your easy endurance running happens between about 110 and 129 bpm.

3. The Karvonen variant (with resting heart rate)

If you know your resting heart rate, the Karvonen method refines the zones starting from your heart-rate reserve (the gap between your max HR and your resting HR):

target HR = resting HR + intensity × (max HR - resting HR)

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%) becomes 60 + (0.60 × 124) ≈ 134 bpm and the top (70%) becomes 60 + (0.70 × 124) ≈ 147 bpm. Karvonen zones sit higher and match how efforts feel more closely, because they account for your heart at rest.

To turn an intensity into beats, use HR = percentage × max HR in simple mode, or HR = resting HR + percentage × (max HR - resting HR) in Karvonen mode.

Chart: max HR and zones by age

Max HR estimated with the Tanaka formula (208 - 0.7 × age), then the training zone boundaries in beats per minute. Benchmarks as % of max HR: ~60% at the bottom of easy running, ~70% for easy endurance, ~80% at low threshold, ~90% at high threshold.

AgeMax HR60%70% (easy)80% (low threshold)90% (high threshold)
20194 bpm116 bpm136 bpm155 bpm175 bpm
25191 bpm115 bpm134 bpm153 bpm172 bpm
30187 bpm112 bpm131 bpm150 bpm168 bpm
35184 bpm110 bpm129 bpm147 bpm166 bpm
40180 bpm108 bpm126 bpm144 bpm162 bpm
45177 bpm106 bpm124 bpm142 bpm159 bpm
50173 bpm104 bpm121 bpm138 bpm156 bpm
55170 bpm102 bpm119 bpm136 bpm153 bpm
60166 bpm100 bpm116 bpm133 bpm149 bpm

These values are benchmarks as a percentage of max HR. The calculator above refines your 5 zones with your resting heart rate (Karvonen method) for a more personal fit.

Frequently asked questions

How do I calculate my maximum heart rate?

Without a stress test, it’s estimated from your age. Three formulas are the references: the classic one, max HR = 220 - age; Tanaka, max HR = 208 - 0.7 × age; and Gellish, max HR = 207 - 0.7 × age. This calculator shows all three. Tanaka’s formula is now considered the most accurate across a broad population, so it’s the default for your zones.

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 and more accurate on average. No formula replaces a real measurement during exercise, though.

What are the 5 heart-rate zones for?

Heart-rate zones split effort by intensity, from Z1 (recovery) to Z5 (VO₂max). They let you steer your training by heart rate: most of your volume goes into Z1 and Z2 (endurance), a little into Z3, and Z4 and Z5 are saved for hard sessions. Following your zones keeps you from running easy days too fast and hard sessions too soft.

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 + intensity × (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). Enter your resting heart rate in the calculator to turn it on.

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.

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