Heart Rate Zone Calculator
Five training zones from max HR, HR reserve, or threshold.
Three ways to set zones
% Max HR is the simplest: each zone is a band of your maximum heart rate. Karvonen (heart-rate reserve) also factors in your resting heart rate, which personalises the bands to your fitness. LTHR anchors the zones to your lactate-threshold heart rate, the Friel approach favoured by many endurance coaches because threshold is more trainable and repeatable than true max.
The five zones
Z1 Recovery and Z2 Aerobic build your base and should feel easy. Z3 Tempo is steady, moderately hard work. Z4 Threshold sits around the edge of sustainable, and Z5 VO₂max is short, very hard efforts. Most endurance training time should live in Z1–Z2.
Finding your numbers
If you do not know your max HR, the age estimate (208 − 0.7 × age) is a reasonable starting point, but a hard field test is more accurate. LTHR is best taken as your average heart rate over the last 20 minutes of a 30-minute all-out time trial.
Questions
Which method should I use?
Heart-rate reserve (Karvonen) is more personal because it uses your resting HR, not just your max. If you know your lactate threshold HR from a field test, the threshold-based zones are the most accurate of all.
How do I find my max heart rate?
A hard, supervised field test is best. If you only have your age, the calculator can estimate it with the Tanaka formula (208 − 0.7 × age), which is more accurate for most adults than the old 220 − age.
What are the zones for?
Roughly: Zone 1 recovery, Zone 2 aerobic base, Zone 3 tempo, Zone 4 threshold, Zone 5 VO₂max. Most endurance training should be easy (Zones 1–2) with smaller doses of hard work.