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Free Heart Rate Zone Calculator

Calculate your max heart rate and 5 training zones by age. Find optimal fat burn, cardio, and threshold heart rate ranges.

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Max Heart Rate

190 BPM

Zone 1 - Recovery

Easy effort, warm-up/cool-down

95-114 BPM

Zone 2 - Fat Burn

Light effort, fat burning, endurance

114-133 BPM

Zone 3 - Cardio

Moderate effort, aerobic fitness

133-152 BPM

Zone 4 - Threshold

Hard effort, speed & power

152-171 BPM

Zone 5 - Max

Maximum effort, short bursts only

171-190 BPM

Formula

Max HR = 220 − Age — zones are calculated as percentages of max heart rate (50-100%)

How Heart Rate Training Zones Work

Heart rate training zones divide your effort into five intensity levels based on your maximum heart rate. Training in specific zones targets different fitness goals — from easy recovery to maximum performance. This calculator uses the age-predicted max heart rate formula (220 − age) to determine your personal zones.

Understanding your zones helps you train smarter, not just harder. Each zone triggers different physiological responses in your body, from fat oxidation in lower zones to lactate threshold improvements in higher zones.

The Five Heart Rate Zones Explained

  • Zone 1 (50-60%): Very light effort. Used for warm-ups, cool-downs, and active recovery days. You can easily hold a full conversation.
  • Zone 2 (60-70%): Light effort. The foundation of endurance training. Burns a high percentage of fat calories. You can talk in complete sentences.
  • Zone 3 (70-80%): Moderate effort. Improves aerobic capacity and cardiovascular efficiency. Speaking becomes harder — short sentences only.
  • Zone 4 (80-90%): Hard effort. Trains your lactate threshold, improving speed and power. You can only manage a few words at a time.
  • Zone 5 (90-100%): Maximum effort. Used for short intervals only. Develops peak speed and anaerobic power. Speaking is impossible.

How to Use Heart Rate Zones for Your Goals

Weight loss: Focus on Zone 2 for longer sessions (45-60 minutes) to maximize fat burning, and mix in Zone 4 intervals to boost total calorie burn.

Endurance: Spend most of your training time in Zones 1-2. Long, slow distance (LSD) runs build the aerobic base that supports all other training.

Speed and performance: Include Zone 4 tempo runs and Zone 5 interval sessions 1-2 times per week, with plenty of Zone 1-2 recovery between hard efforts.

Tips for Accurate Heart Rate Monitoring

  • Use a chest strap for the most accurate real-time readings during exercise
  • Measure resting HR first thing in the morning before getting out of bed
  • Avoid caffeine before testing — it can elevate your heart rate by 5-15 BPM
  • Account for conditions — heat, altitude, stress, and dehydration all raise heart rate

Frequently Asked Questions

How do I find my max heart rate?

The simplest formula is 220 minus your age. For a 30-year-old, that's 190 BPM. This is an estimate — your actual max HR can vary by 10-20 BPM. For a more accurate number, you can do a supervised max HR test or use the Tanaka formula (208 − 0.7 × age).

Which heart rate zone burns the most fat?

Zone 2 (60-70% of max HR) is often called the fat-burning zone because a higher percentage of calories come from fat at this intensity. However, higher-intensity zones burn more total calories per minute, which can lead to greater overall fat loss.

How long should I train in each zone?

Most fitness experts recommend spending 80% of your training time in Zones 1-2 (easy/moderate effort) and 20% in Zones 3-5 (hard effort). This is called the 80/20 rule and helps build endurance while preventing overtraining.

What's the Karvonen method?

The Karvonen method uses your heart rate reserve (max HR minus resting HR) for more personalized zones. The formula is Target HR = Resting HR + (HR Reserve × % Intensity). It's more accurate because it accounts for your fitness level through resting heart rate.

Is it dangerous to exercise in Zone 5?

Zone 5 (90-100% max HR) is safe for healthy individuals in short bursts, like during interval training. However, you shouldn't sustain Zone 5 for long periods. If you have heart conditions, consult your doctor before high-intensity exercise.