Target Heart Rate (THR) Zone Calculator
Calculate your personalized target heart rate training zones using the clinically validated Karvonen formula based on your age and resting heart rate.
Cardio Profile
Region & Benchmark
Your Target Heart Rate Zone
beats per minute (BPM)
Cardio Endurance / Aerobic · 70–80% intensity
Max HR
190
BPM
Reserve (HRR)
125
BPM
Zone Width
13
BPM range
Heart Rate Zone Spectrum
AHA Benchmark
American Heart Association (AHA) standards recommend 50–70% of maximum heart rate for moderate-intensity activity and 70–85% for vigorous cardio, with anaerobic training reserved for short intervals under medical guidance.
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Overview
The Target Heart Rate (THR) Zone Calculator helps athletes and fitness enthusiasts calculate their optimal training intensity zones using the clinically validated Karvonen Formula. By analyzing individual age profiles and physiological resting heart rates, this system maps out safe cardio boundaries to optimize fat oxidation and cardiac endurance without overtraining.
Formula
The calculation utilizes physiological telemetry metrics known as the Karvonen Method:
1. Maximum Heart Rate: HRmax = 220 − Age 2. Heart Rate Reserve: HRR = HRmax − Resting Heart Rate 3. Target Heart Rate Range: THR = (HRR × Intensity Percentage) + Resting Heart Rate The Karvonen model is significantly more accurate than basic age-based metrics because it introduces personal resting cardiovascular baseline data.
Practical Example
A 30-year-old US runner has an athletic resting heart rate of 65 BPM and wants to calculate their "Cardio Endurance / Aerobic" zone (70% to 80% intensity). HRmax Calculation: 220 − 30 = 190 BPM. HRR Calculation: 190 − 65 = 125 BPM. Lower Target Limit (70%): (125 × 0.70) + 65 = 87.5 + 65 = 152.5 BPM. Upper Target Limit (80%): (125 × 0.80) + 65 = 100 + 65 = 165 BPM. The runner should maintain a steady pulse between 153 and 165 beats per minute during workouts.