Which max heart rate formula is most accurate?

The Tanaka formula (208 minus 0.7 times age) is generally more accurate across ages than the classic 220-minus-age (Haskell) formula. Gulati (206 minus 0.88 times age) was developed specifically for women.

What is the Karvonen method?

Karvonen calculates training zones from your heart-rate reserve — the gap between your resting and maximum heart rate — rather than a flat percentage of max. It is more personalised, which is why the calculator switches to it automatically when you enter a resting heart rate.

No. Every calculation runs in your browser and nothing is sent to a server.

What are the five heart-rate training zones?

Zone 1 (50-60% of max) is very light warm-up and recovery, Zone 2 (60-70%) is light fat-burn base work, Zone 3 (70-80%) is moderate aerobic endurance, Zone 4 (80-90%) is hard anaerobic-threshold work, and Zone 5 (90-100%) is maximum VO2-max and sprint effort.

How are the zones calculated without a resting heart rate?

Without a resting heart rate the zones are simple percentages of your estimated maximum — for example Zone 3 is 70-80% of max HR. Enter a resting heart rate and the tool switches to the Karvonen method, which applies those percentages to your heart-rate reserve instead.

How accurate is an age-based maximum heart rate?

Age formulas are population estimates with a typical spread of about plus or minus 10-12 beats per minute, so two people of the same age can have genuinely different maxima. For an exact figure you need a supervised graded exercise (stress) test.

What is heart-rate reserve?

Heart-rate reserve is the difference between your maximum and resting heart rate — the range your heart can work across. The Karvonen method bases each training zone on a percentage of this reserve added to your resting rate, giving more personalised targets than a flat percentage of max.

Max Heart Rate Calculator

Your maximum heart rate (MHR) is the highest beats-per-minute your heart can reach at all-out effort, and it sets the boundaries for your training zones. This calculator estimates MHR from your age using four research-backed formulas and breaks the result into five zones, from easy recovery to maximum effort — useful for runners, cyclists and anyone training to a heart-rate monitor.

How it works

Choose an age-based formula:

Formula	Equation	Best for
Tanaka	`208 − 0.7 × age`	most adults (most accurate)
Haskell & Fox	`220 − age`	the classic rule of thumb
Gulati	`206 − 0.88 × age`	women
Nes	`211 − 0.64 × age`	general adult population

The five zones are then taken as percentages of that maximum: Zone 1 (50-60%), Zone 2 (60-70%), Zone 3 (70-80%), Zone 4 (80-90%) and Zone 5 (90-100%). If you also enter a resting heart rate, the tool switches to the Karvonen method, applying each percentage to your heart-rate reserve (max − resting) and adding back the resting rate for more personalised targets.

Example

A 30-year-old using the Tanaka formula: MHR = 208 − 0.7 × 30 = 187 bpm. The Zone 2 band (60-70%) is 187 × 0.60 to 187 × 0.70 ≈ 112-131 bpm. Add a resting rate of 60 bpm and Karvonen recalculates Zone 2 as 60 + (127 × 0.60) to 60 + (127 × 0.70) ≈ 136-149 bpm.

Everything runs in your browser, so nothing is uploaded. Age-based estimates carry a typical error of around ten beats per minute — treat them as a guide, and check with a doctor before starting intense exercise.