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American Heart Association Heart Rate Calculator

Calculate your Target Heart Rate (THR) zones and Maximum Heart Rate based on the official American Heart Association (AHA) guidelines.

Your Age (Years)

Your Heart Rate Zones

Maximum Heart Rate (MHR): — bpm

Moderate Intensity Zone (50-70%): — bpm

Vigorous Intensity Zone (70-85%): — bpm

*bpm = beats per minute. These figures are estimates based on age.

Please enter a valid age between 1 and 120.

Understanding Your Numbers

According to the American Heart Association (AHA), knowing your target heart rate helps you track the intensity of your physical activities. Whether you are aiming for weight loss, cardiovascular endurance, or general health maintenance, staying within these zones ensures you are exercising safely and effectively.

How the Calculation Works

This calculator uses the standard formulas recommended by heart health organizations:

Maximum Heart Rate (MHR): Calculated as 220 - Your Age. This is the estimated upper limit of what your cardiovascular system can handle during physical stress.
Moderate Intensity (50% to 70%): This is the "fat burning" zone. You should be able to carry on a conversation, but you will be breathing heavier than normal.
Vigorous Intensity (70% to 85%): This is the cardio zone. Your breathing will be deep and rapid, and you will likely break a sweat after a few minutes.

AHA Recommendation: The AHA recommends at least 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous activity per week for adults to maintain good cardiovascular health.

Why Monitor Your Heart Rate?

Monitoring your heart rate prevents you from under-training (not getting enough benefit) or over-training (risking injury). If your heart rate is too high, you are straining yourself. If it is too low, the intensity may not be sufficient to improve fitness levels.

Frequently Asked Questions

Can I exceed my Maximum Heart Rate?

It is generally not recommended to exceed your calculated maximum heart rate for extended periods. The MHR is an estimate; if you find you can easily exceed this number, your true maximum may be higher, but you should consult a doctor before pushing limits.

What factors affect heart rate?

Aside from age, factors such as medication, stress, caffeine intake, temperature, and overall fitness level can influence your resting and active heart rates. This calculator provides a baseline estimate for the general population.

function calculateHeartRate() { // 1. Get input var ageInput = document.getElementById('inputAge').value; var errorMsg = document.getElementById('errorMsg'); var resultsDiv = document.getElementById('results'); // 2. Validate input var age = parseFloat(ageInput); if (isNaN(age) || age 120) { errorMsg.style.display = 'block'; resultsDiv.style.display = 'none'; return; } // Hide error if valid errorMsg.style.display = 'none'; // 3. Logic: AHA Standard Formula // MHR = 220 – age var maxHeartRate = 220 – age; // Moderate Intensity: 50% to 70% of MHR var modMin = Math.round(maxHeartRate * 0.50); var modMax = Math.round(maxHeartRate * 0.70); // Vigorous Intensity: 70% to 85% of MHR var vigMin = Math.round(maxHeartRate * 0.70); var vigMax = Math.round(maxHeartRate * 0.85); // 4. Update UI document.getElementById('resMaxHeartRate').innerHTML = maxHeartRate + " bpm"; document.getElementById('resModerateZone').innerHTML = modMin + " – " + modMax + " bpm"; document.getElementById('resVigorousZone').innerHTML = vigMin + " – " + vigMax + " bpm"; // Show results resultsDiv.style.display = 'block'; }