Heart Rate Zone Calculator

Heart rate zones divide exercise intensity into 5 levels based on percentage of max heart rate. Zone 1 (50-60%): very light, warm-up. Zone 2 (60-70%): fat burning, endurance base. Zone 3 (70-80%): aerobic, moderate effort. Zone 4 (80-90%): anaerobic threshold, hard effort. Zone 5 (90-100%): maximum effort, sprints.

The most common formula is 220 minus your age. A 30-year-old has an estimated max HR of 190 bpm. The Tanaka formula (208 - 0.7 x age) is considered more accurate for older adults. These are estimates — actual max HR varies by +-10-15 bpm between individuals. A supervised max HR test gives the most accurate number.

HRR = Max Heart Rate - Resting Heart Rate. The Karvonen method uses HRR for more personalized zones: Target HR = (HRR x intensity%) + Resting HR. For a 30-year-old with resting HR 60: HRR = 190-60 = 130. Zone 2 (60-70%): 60 + (130 x 0.6) to 60 + (130 x 0.7) = 138-151 bpm.

Zone 2 (60-70% max HR) uses the highest percentage of fat for fuel, but total calorie burn is lower due to moderate intensity. Higher zones burn more total calories (and more total fat calories) per minute despite a lower fat percentage. For weight loss, total calorie burn matters more than the "fat burning zone." Train at whatever intensity you can sustain.

Most training plans use zone-based periodization. Endurance base building: 80% of training in Zone 2. Tempo runs: Zone 3-4. Intervals: Zone 4-5 with Zone 1-2 recovery. A typical weekly split for distance runners: 3-4 easy Zone 2 runs, 1 tempo (Zone 3-4), 1 interval session (Zone 4-5), 1 long slow run (Zone 2).