Overview
Training by heart-rate zone keeps each workout at the right intensity — easy days easy and hard days hard. This calculator finds your maximum heart rate and five personalised zones using your resting heart rate.
How it's calculated
Enter your age and resting heart rate (measure it first thing in the morning). We estimate max HR with the Tanaka formula, then apply the Karvonen heart-rate-reserve method to map five zones from recovery (50–60%) to maximal (90–100%).
max HR = 208 − 0.7 × age (Tanaka) zone bpm = resting + %×(max − resting) (Karvonen)
How to read your result
Most endurance training should sit in Z2 (aerobic base); Z4–Z5 are reserved for intervals. The Karvonen method personalises zones using your resting heart rate, so they're more accurate than a flat percentage of max HR.
Frequently asked questions
Why use Tanaka over 220 − age?
The classic 220 − age formula is less accurate across ages. Tanaka (208 − 0.7×age) better fits the data, especially for older athletes.
What's the Karvonen method?
It bases zones on heart-rate reserve (max minus resting) rather than max alone, personalising them to your fitness level.
Which zone should I train in?
Build most volume in Z2 for an aerobic base, with limited time in Z4–Z5 for intervals. The exact mix depends on your goal.
Sources & references
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 2001;37(1):153-156.
- Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate. Ann Med Exp Biol Fenn. 1957;35(3):307-315.
Medical disclaimer
This calculator is for general educational purposes only and is not medical advice. Estimates are based on population formulas and may not fit your individual situation. Consult a qualified healthcare or fitness professional before making health, nutrition or training decisions.