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Target Heart Rate Calculator

Calculate target heart rate zones for fat burning, cardio, and peak performance. Find max heart rate by age using Karvonen method.

Measure first thing in the morning. Normal: 60–100 bpm.

Max Heart Rate

190 bpm

220 − 30 (Haskell formula)

Warm-up

50–60% · Recovery & light cardio

128140 bpm

Fat Burn

60–70% · Fat oxidation & endurance base

140153 bpm

Aerobic

70–80% · Cardiovascular fitness

153165 bpm

Anaerobic

80–90% · Speed & lactate threshold

165178 bpm

VO2 Max

90–100% · Maximum performance

178190 bpm

About the Target Heart Rate Calculator

Training in the right heart rate zone is the difference between an effective workout and an ineffective one. Too slow and you miss cardiovascular adaptation; too hard and you cannot sustain it long enough for meaningful benefit. Our target heart rate calculator uses the Karvonen formula — which factors in your resting heart rate for greater precision — to define your five training zones from warm-up to VO2 max.

Formula

THR = ((Max HR − Resting HR) × Intensity%) + Resting HR

How It Works

Maximum heart rate estimate: MHR = 220 − age (traditional) or 208 − 0.7 × age (Tanaka formula, more accurate for older adults). The Karvonen formula for target heart rate: THR = ((MHR − RHR) × %intensity) + RHR, where RHR is your resting heart rate measured first thing in the morning. The five zones: Zone 1 (50-60%), Zone 2 fat burn (60-70%), Zone 3 aerobic (70-80%), Zone 4 anaerobic threshold (80-90%), Zone 5 VO2 max (90-100%).

Tips & Best Practices

  • Measure resting heart rate on 3 consecutive mornings and average for best accuracy.
  • Zone 2 training (conversational pace) builds aerobic base — most elite runners do 80% of runs here.
  • Zone 4 training near lactate threshold builds race pace speed — keep sessions to 20-40 minutes.
  • High-intensity interval training alternates Zone 4-5 with Zone 1-2 recovery.
  • Wearable devices (Apple Watch, Garmin) measure HR continuously but have errors of ±5-10 BPM during exercise.

Who Uses This Calculator

Endurance athletes structuring training periodisation, cardiac rehab patients with physician-prescribed heart rate limits, fitness enthusiasts using heart rate monitors, and coaches designing group fitness class intensity all use target heart rate zones.

Optimised for: USA · Canada · UK · Australia · Calculations run in your browser · No data stored

Frequently Asked Questions

What is the fat-burning heart rate zone?

The fat-burning zone is 50–70% of max heart rate. For a 35-year-old (max HR ~185), that's 93–130 bpm.