Heart Rate Zone Calculator
Training by heart rate helps you run, ride and train at the right effort. Enter your age (or measured max heart rate) and, optionally, your resting heart rate to get your five heart rate zones in beats per minute, including your zone 2 endurance range.
Heart rate training divides cardiovascular effort into 5 zones: Zone 1 (Active Recovery, 50-60%), Zone 2 (Aerobic Endurance, 60-70%), Zone 3 (Tempo, 70-80%), Zone 4 (Threshold, 80-90%), and Zone 5 (Neuromuscular/VO2 Max, 90-100%). Karvonen Heart Rate Reserve (HRR) provides individualized precision when resting heart rate is known.
Zone 2 Endurance Heart Rate
Karvonen (HRR)Zone 2 builds mitochondrial density, fat oxidation and aerobic base. You should be able to hold a conversation in full sentences comfortably.
Max Heart Rate
180 bpm
Karvonen (HRR)
Resting Heart Rate
60 bpm
HRR applied
Zone 2 10s Pulse
22–24 beats
Count wrist for 10s
5-Zone Training Matrix
| Zone | Intensity | Target BPM | 10-Sec Pulse |
|---|---|---|---|
| Zone 1 | Very Light (50–60%) | 120 – 132 | 20–22 beats |
| Zone 2 | Light / Endurance (60–70%) | 132 – 144 | 22–24 beats |
| Zone 3 | Moderate / Tempo (70–80%) | 144 – 156 | 24–26 beats |
| Zone 4 | Hard / Threshold (80–90%) | 156 – 168 | 26–28 beats |
| Zone 5 | Maximum / VO2 Max (90–100%) | 168 – 180 | 28–30 beats |
Karvonen Heart Rate Reserve (HRR) adjusts each zone to your resting heart rate for higher accuracy.
100% Device-Local
Inputs never leave your browser
Instant Live Maths
Calculates in real time as you type
Clinical Equations
WHO, CDC, ACSM & Mifflin-St Jeor
Suggest a Feature or Improvement for Heart Rate Zone Calculator
Need custom options, higher limits, or extra format support? Let our engineering team know!
How to use Heart Rate Zone Calculator
- 1Enter your age or your directly measured maximum heart rate.
- 2Optionally enter your waking resting heart rate to enable the Karvonen formula.
- 3Review your personalized BPM target ranges for Zone 1 through Zone 5.
The 5 Heart Rate Training Zones
Zone 1 (50–60%): Active recovery, warm-up, and cool-down. Zone 2 (60–70%): Aerobic base building, mitochondrial density, and fat oxidation. Zone 3 (70–80%): Aerobic endurance and tempo training.
Zone 4 (80–90%): Lactate threshold and high aerobic power. Zone 5 (90–100%): Anaerobic capacity, VO2 max intervals, and sprint power.
Why Zone 2 is essential
Zone 2 training stimulates mitochondrial biogenesis and enhances your body's ability to clear lactate. Elite endurance runners and cyclists spend roughly 80% of their weekly training volume inside Zone 2.
Frequently Asked Questions
What is zone 2 heart rate?
Zone 2 represents roughly 60 to 70% of your maximum heart rate (or 60–70% of Heart Rate Reserve). It corresponds to an easy conversational pace where you can speak in full sentences.
What's the best max heart rate formula?
The Tanaka formula (208 − 0.7 × age) is significantly more accurate across broad adult age groups than the traditional 220 − age formula.
Why use resting heart rate?
The Karvonen Heart Rate Reserve (HRR) formula factors in your cardiovascular fitness baseline. A lower resting heart rate indicates greater stroke volume, shifting your functional training zones higher.
Do heart rate zones work on beta-blockers?
Beta-blockers artificially suppress heart rate. If you take cardiovascular medications, use the Borg Rating of Perceived Exertion (RPE) instead and consult your cardiologist.
Related Calculators
Running Pace Calculator
Calculate pace, time, or distance for running with splits for 5K, 10K, half marathon, and marathon.
TDEE Calculator
Estimate your Total Daily Energy Expenditure and discover your true maintenance calories.
Water Intake Calculator
Calculate your optimal daily fluid intake based on body weight, workout intensity, and climate.
Scientific Sources & Evidence
- World Health Organization (WHO) — Body Mass Index Classification
- CDC Growth Charts — BMI-for-age LMS Percentiles
- Mifflin et al. (1990) — Basal Metabolic Rate Predictive Equations
- NICE Guideline NG246 — Identification and Management of Overweight and Obesity
- American College of Sports Medicine (ACSM) — Exercise Testing & Prescription
- European Food Safety Authority (EFSA) — Dietary Reference Values for Water