Heart Rate Zone Calculator
Free online heart rate zone calculator. No sign-up, no installation. Runs entirely in your browser.
Method: Max heart rate is estimated as 220 − age; zones use the Karvonen heart-rate-reserve formula.
Calculate Your Training Zones
What is a Heart Rate Zone?
A heart rate zone is a range of heartbeats per minute that represents a specific intensity level during exercise. Training in different zones produces different physiological adaptations—building aerobic capacity, improving threshold, or allowing recovery. Understanding your personal zones helps you structure more effective workouts and ensures you're training at the right intensity for your fitness goals.
How to Use This Calculator
Enter your age and optionally your resting heart rate. The Simple Method uses the standard formula (220 − Age) and works for most people. For greater accuracy, enter your resting heart rate and select the Karvonen Method, which accounts for your individual fitness level. The calculator displays all five training zones with specific BPM ranges, benefits, and recommended training durations for each zone.
Training Zone Use Cases
Recovery Zone (Zone 1): Easy warm-ups and active recovery days. Aerobic Zone (Zone 2): Building endurance and fat-burning base. Tempo Zone (Zone 3): Improving lactate threshold and work capacity. Threshold Zone (Zone 4): High-intensity intervals and VO₂ max development. Max Zone (Zone 5): Peak sprints and maximum effort. Balanced training across zones is more effective than staying in one zone.
Frequently Asked Questions
What's the difference between the Simple and Karvonen methods?
The Simple Method (220 − Age) is a quick general estimate. The Karvonen Method uses your resting heart rate to calculate a personalized maximum heart rate reserve, making it significantly more accurate for trained athletes and people with naturally low resting rates.
How do I measure my resting heart rate?
Measure your pulse first thing in the morning before getting out of bed, or after sitting quietly for 10+ minutes. Count your heartbeats for 15 seconds and multiply by 4, or count for a full 60 seconds. A typical resting heart rate is 60–100 BPM; trained athletes often have 40–60 BPM.
Should I train in just one zone?
No. Effective training uses multiple zones. The general rule is 80% easy work (Zones 1–2) and 20% harder work (Zones 3–5). This mix builds aerobic capacity, allows recovery, and triggers high-intensity adaptations without overtraining.
How often should I recalculate my zones?
Recalculate annually or whenever your fitness level changes significantly. If using the Karvonen Method, remeasure your resting heart rate every 3–6 months, as it may improve with consistent training.
What if my calculated zones don't match my perceived effort?
These calculations are estimates based on population averages. If zones feel off, consider a max heart rate test (sprint to exhaustion) to find your actual maximum. You can also use a fitness watch with continuous heart rate monitoring to fine-tune your zones in real workouts.
Can I use this if I take heart rate–affecting medication?
Some medications (beta blockers, certain antidepressants) significantly lower maximum heart rate. Consult your doctor before relying on calculated zones. You may need to base training on perceived exertion, wattage, or pace instead of heart rate.