Enter your age and resting heart rate to calculate personalised target heart rate zones using the Karvonen method. This accounts for your individual fitness level, producing more accurate zones than simple percentage-of-max formulas.
Maximum heart rate is estimated using the Tanaka formula: Max HR = 208 − (0.7 × age). Each training zone is a percentage range of max HR. When a resting heart rate is provided, the Karvonen method is used instead: Target HR = ((Max HR − Resting HR) × intensity%) + Resting HR. This accounts for heart rate reserve and produces personalised zones. All arithmetic runs locally in your browser using pure JavaScript.
All calculations happen locally using pure JavaScript. Our servers are not involved at any point.
The Tanaka formula (208 − 0.7 × age) was derived from a meta-analysis of 351 studies involving 18,712 subjects by Tanaka et al. and published in the Journal of the American College of Cardiology 37:1 (2001). It is more accurate than the classic 220 − age formula across all age groups, particularly for adults over 40. Both formulas have a standard deviation of ±10–12 bpm. The Karvonen method uses heart rate reserve (HRR = Max HR − Resting HR) to scale zones relative to individual fitness.
For estimating daily energy expenditure for training, try the calorie calculator. To capture a baseline weight category, use the BMI calculator. For tracking strength gains alongside cardio zones, see the one-rep max calculator.