Heart Rate Zone Calculator

Enter your age to estimate your maximum heart rate using the standard 220-age formula. If you know your actual max HR from a fitness test, check the box and enter it directly for more accurate zones.

Add your resting heart rate for the Karvonen method. Measure it first thing in the morning before getting out of bed. A lower resting heart rate generally indicates better cardiovascular fitness.

Choose between the Max HR Percentage method (simpler, good for general use) and the Karvonen method (accounts for fitness level via resting heart rate).

Zone 1 - Recovery (50-60%): Very light effort. Use for warm-ups, cool-downs, and active recovery days. You should be able to hold a full conversation easily.

Zone 2 - Fat Burn (60-70%): Light effort and the foundation of endurance training. Your body primarily uses fat for fuel. Long, steady sessions in this zone build aerobic base.

Zone 3 - Aerobic (70-80%): Moderate effort that improves cardiovascular efficiency. Breathing becomes heavier but you can still speak in short sentences. Tempo runs and steady-state cycling fall here.

Zone 4 - Anaerobic (80-90%): Hard effort near your lactate threshold. Trains your body to clear lactic acid faster. Interval training and race-pace efforts target this zone.

Zone 5 - VO2 Max (90-100%): Maximum effort sustainable for only short bursts. Develops peak power and speed. Sprint intervals and all-out efforts live here.

The percentage method simply multiplies your max heart rate by the zone percentage. It is straightforward and works well for most recreational exercisers.

The Karvonen method uses heart rate reserve (max HR minus resting HR) and produces zones that better reflect individual fitness. A trained athlete with a resting HR of 50 BPM will get different zones than a sedentary person with a resting HR of 80 BPM, even at the same age.

For serious training, the Karvonen method is generally recommended because it accounts for cardiovascular fitness. The percentage method is adequate for general fitness and weight management goals.

Use a heart rate monitor for accurate real-time feedback. Chest straps are more accurate than optical wrist sensors, especially during high-intensity or interval work.

Cardiac drift means your heart rate can rise over a long session even at constant effort. This is normal, especially in heat. Focus on perceived effort alongside heart rate data.

Medications and caffeine can affect heart rate. Beta-blockers lower max HR, while caffeine and decongestants can raise it. Factor these in when interpreting your zones.