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HR zones.

Five training zones from your max heart rate — or your reserve, if you know your resting HR. The Karvonen method gives you personalized intensities; the Tanaka formula estimates max HR when you don't have a tested number.

MAX HEART RATE
184bpm
Tanaka formula · 208 − 0.7 × 35
ZONEBPM% HRPURPOSE
Zone 1 — Easy
Comfortable conversational pace
120–14565–79%Aerobic base, recovery, fat burning
Zone 2 — Marathon
Steady effort, marathon pace
147–15680–85%Sustained aerobic endurance
Zone 3 — Threshold
Comfortably hard, tempo runs
156–16685–90%Improve lactate clearance
Zone 4 — Interval
Hard effort, VO2max work
175–18495–100%Maximize oxygen uptake
Zone 5 — Repetition
Max effort, short bursts
184–184100–110%Speed and neuromuscular power
METHODOLOGY

How this calculator works

  1. Karvonen heart-rate-reserve method

    Zones are calculated as a percentage of heart-rate reserve (HRR = max HR − resting HR) added back to resting HR. This is more individualized than the simpler "%HRmax" method because it accounts for your resting HR, which differs widely between trained and untrained runners.

    M. J. Karvonen, "The effects of training on heart rate; a longitudinal study," Annales Medicinae Experimentalis et Biologiae Fenniae, vol. 35, no. 3, 1957, pp. 307–315.

  2. Tanaka–Monahan–Seals max-HR estimate

    Estimates max heart rate as 208 − 0.7 × age. Tanaka et al. found this fit observed data better across age groups than the older 220 − age formula. PaceCalc uses Tanaka by default; you can override with a measured max HR if you have one.

    H. Tanaka, K. D. Monahan, D. R. Seals, "Age-predicted maximal heart rate revisited," Journal of the American College of Cardiology, vol. 37, no. 1, 2001, pp. 153–156.

NOTES
  • Karvonen is most useful when you know your resting HR (early-morning, lying down, multiple-day average). If you do not, use the simpler %HRmax fallback we surface.
FAQ

Frequently asked

How do I find my maximum heart rate?
The most accurate method is a supervised max HR test. The Tanaka formula (208 - 0.7 × age) provides a good estimate. The old '220 minus age' formula is less accurate. Individual variation can be ±10-15 BPM.
What is the Karvonen formula?
The Karvonen method uses your heart rate reserve (max HR minus resting HR) to calculate zones, making them more personalized. If you know your resting HR, this method gives more accurate zone boundaries than simple percentage of max HR.
Which heart rate zone burns the most fat?
Zone 1 (Easy, 65-79% max HR) uses the highest percentage of fat for fuel, but higher zones burn more total calories. For overall fitness and weight management, a mix of zones is most effective.
Why are my HR zones different from my watch?
Different devices use different zone systems. Some use 3 zones, others 5 or 7. Our zones are based on the Jack Daniels training system which aligns with running-specific training purposes. Use the zones that match your training plan.
How does resting heart rate affect training zones?
A lower resting HR means a larger heart rate reserve, which shifts your training zones higher. Athletes with resting HRs of 45-55 BPM will have different zone boundaries than those at 65-75 BPM, even with the same max HR.