top of page
Target Heart-Rate (THR) Calculator
Determine your ideal cardio training range using the Karvonen method — factoring in resting heart-rate for a more accurate target zone.
Why aim for 50–85%?
Below this range there's little cardio conditioning or fat-burning going on. Above it you cross into anaerobic territory — great for HIIT and sprinting, but a different physiological mechanism. Most health institutes (including the American Heart Association) recommend 50–85% of your maximum heart rate for 20–30 minutes per session.
HRmax = 220 − age
Karvonen THR = ((HRmax − HRrest) × intensity) + HRrest
1
Enter Your Age and Resting Heart Rate
Age:
Resting Heart Rate:
bpm (ideally measured first thing in the morning)
2
Your Target Heart Rate Range
HR max
Lower (50%)
Upper (85%)
bottom of page