Heart Rate Zone Calculator

Calculate your maximum heart rate and the five training zones.

Please note: For general information only. This is not medical advice — speak to a doctor or registered dietitian before changing your diet, training or medication.

What the Heart Rate Zone Calculator does

Training zones divide your heart rate range into intensity bands with different physiological effects. The Karvonen method, which uses your resting heart rate, personalises the zones better than a plain percentage of maximum.

Formula

Tanaka max HR = 208 − 0.7 × age
Classic max HR = 220 − age
Karvonen: Target = Resting + (Max − Resting) × intensity

Inputs explained

Input	Unit	Required	Notes
Age	years	Yes	Accepts 10 or more, up to 120.
Resting heart rate	bpm	Optional	Optional — enables the more accurate Karvonen method. Accepts 30 or more, up to 120.
Max HR formula	one of 2 options	Yes	—

How to use it

Choose Max HR formula.
Enter Age.
Optionally add Resting heart rate.
Select Calculate.

Worked example

A 40-year-old with a resting heart rate of 60 bpm.

Age: 40
Resting: 60
Formula: Tanaka

Max HR 180, reserve 120. Zone 2 works out at 132–144 bpm.

Frequently asked questions

Is 220 minus age accurate?

It is easy to remember but has a standard deviation of about 10–12 bpm. The Tanaka formula fits the population data better, especially for older athletes.

Why train in zone 2?

It builds aerobic base and mitochondrial density while staying sustainable. Most endurance programmes put the large majority of volume there.

Method and sources

Method. Maximum heart rate is estimated by the Tanaka equation (208 − 0.7 × age) or the classic 220 − age, and zones are derived either as percentages of that maximum or, where a resting rate is supplied, by the Karvonen heart-rate-reserve method.

Assumptions

The reader is not taking medication that alters heart rate. Beta blockers in particular lower both maximum and working heart rate, which invalidates every zone here.
Resting heart rate, where used, was measured at rest rather than shortly after activity.

Limitations

Age-predicted maximum heart rate is a population average with wide individual scatter — published standard deviations are around ten beats per minute, so an individual can sit well outside their predicted zone.
Zone boundaries are conventions, not physiological thresholds. A measured lactate or ventilatory threshold is a different and more accurate basis for training.
Not appropriate for anyone with a cardiac condition or returning from illness without medical guidance.

Sources

Age-predicted maximal heart rate revisited — Journal of the American College of Cardiology 37(1):153–156 (Tanaka, Monahan and Seals), 2001. The 208 − 0.7 × age maximum heart rate equation offered as the default.
The effects of training on heart rate: a longitudinal study — Annales Medicinae Experimentalis et Biologiae Fenniae 35:307–315 (Karvonen, Kentala and Mustala), 1957. The heart-rate-reserve method used when a resting heart rate is supplied.