Heart Rate Zone Calculator

Estimate training zones from multiple MHR formulas

All calculations run in your browser. Change age and formula to instantly update training zones in bpm and % of max heart rate.

Haskell & Fox

Estimated max heart rate (MHR)

Healthy cardio target range (50-85% MHR)

General guidance for moderate-to-vigorous cardio sessions.

Heart rate training zones

Zone	% of MHR	Range (bpm)

Training zone visualization

Zone	% of MHR	Effort level	Benefits
Zone 1: Very Light	50-60%	Very easy, warm-up, cool-down	Improves overall health, recovery, fat metabolism
Zone 2: Light (Fat-Burning Zone)	60-70%	Comfortable pace, can talk easily	Improves basic endurance, fat utilization
Zone 3: Moderate (Aerobic Zone)	70-80%	Steady effort, harder breathing	Builds aerobic fitness, improves circulation, strengthens heart
Zone 4: Hard (Anaerobic Zone)	80-90%	Challenging, conversation difficult	Improves VO2 max, lactate threshold, speed and performance
Zone 5: Maximum Effort	90-100%	Near max effort, short bursts	Peak performance, sprint training, increases power

Age group	Normal range (bpm)	Notes
Newborn (0-1 month)	100-180	Higher due to immature heart and higher metabolism
Infant (1-12 months)	100-160	Still elevated compared to older children
Toddler (1-2 yrs)	100-140	Starts to slow down as heart grows
Preschool (3-5 yrs)	80-120
School-age (6-12 yrs)	75-120	Closer to adult ranges
Adolescent (13-18 yrs)	60-100	Similar to adult resting range
Adults (18+ yrs)	60-100	Well-trained athletes: 40-60
Older Adults (65+ yrs)	60-100	May trend slightly higher due to reduced cardiac efficiency

Resting Heart Rate (RHR): typically 60-100 bpm (often lower in athletes).
Target Heart Rate for Cardio Health: usually 50-85% of MHR during exercise.
Clinical consideration: people with heart conditions should consult a doctor before training near Zone 4-5.