Heart Rate Zone Calculator
Free heart rate zone calculator: get all five training zones in bpm from your age or measured max HR, using percent-of-max or the Karvonen method.
About the Heart Rate Zone Calculator
Training by heart rate zones keeps easy days easy and hard days effective. This free heart rate zone calculator estimates your maximum heart rate as 220 − age (or accepts a measured value) and splits effort into the standard five zones — 50-60% warm-up, 60-70% fat-burn base, 70-80% aerobic, 80-90% threshold and 90-100% maximal — showing each range in actual beats per minute.
It supports two methods: simple percentage of max HR, and the more personalised Karvonen formula, target = (HRmax − HRrest) × intensity + HRrest, which anchors the zones to your heart-rate reserve. Runners, cyclists and gym-goers from Islamabad to Bangalore use these numbers to pace long runs, intervals and recovery days. The 220 − age rule is an estimate — a measured max gives better zones.
How to Use the Heart Rate Zone Calculator
- 1Enter your age, or a measured maximum heart rate if you have one.
- 2Choose the method — % of max HR, or Karvonen for personalised zones.
- 3For Karvonen, add your resting heart rate.
- 4Read all five zone ranges in beats per minute.
Frequently Asked Questions
How are heart rate zones calculated by age?
Estimate max HR as 220 − age, then take percentages. A 35-year-old has an estimated max of 185 bpm, so Zone 2 (60-70%) is 111-130 bpm and Zone 4 (80-90%) is 148-167 bpm. The calculator lists all five zones at once.
What is the Karvonen formula and why use it?
Karvonen uses heart-rate reserve: target = (HRmax − HRrest) × intensity + HRrest. For max 185 and resting 60, Zone 2 becomes (125 × 0.6) + 60 = 135 to (125 × 0.7) + 60 = 148 bpm — noticeably higher than the plain 111-130. It accounts for your fitness via resting HR, so zones fit better.
Which zone burns the most fat?
Zone 2 (60-70%) burns the highest proportion of calories from fat and is where endurance coaches put most training volume. Higher zones burn more total calories per minute though — for weight loss, total weekly calorie burn and consistency matter more than staying in one magic zone.
How accurate is 220 minus age?
It is a population average with a standard deviation around 10-12 bpm — plenty of healthy 40-year-olds max out at 170 or 195 rather than 180. If you train seriously, use a field test or a recent race maximum and enter it as your measured max HR for tighter zones.