Heart Rate Zone Calculator
Calculate your 5 training heart rate zones using age or resting heart rate (Karvonen method).
Zone 1 (50–60%)
Active recovery — very light
93–111 bpm
Zone 2 (60–70%)
Aerobic base — fat burn, long endurance
111–130 bpm
Zone 3 (70–80%)
Tempo — improved aerobic capacity
130–148 bpm
Zone 4 (80–90%)
Threshold — lactate threshold training
148–167 bpm
Zone 5 (90–100%)
VO2 max — anaerobic, short intervals
167–185 bpm
Disclaimer: Heart rate zone calculations are estimates. Individual max HR can vary ±15 bpm from the formula. Consult a physician before beginning intense exercise, especially if you have heart conditions, take medications that affect heart rate, or are pregnant. Not medical advice.
Frequently Asked Questions
What's the difference between age-based and Karvonen?
Age-based uses %MaxHR (220 − age). Karvonen uses heart rate reserve (MaxHR − RestingHR) × %intensity + RestingHR, which accounts for individual fitness and is more accurate for trained athletes.
What does each zone do?
Z1 active recovery, Z2 aerobic base/fat burn, Z3 tempo, Z4 threshold/lactate, Z5 VO2 max/anaerobic. Most endurance training should happen in Z2 (~80% of volume).