Your heart rate is a vital sign that reflects how hard your cardiovascular system is working. During physical activity, your heart rate increases to pump more oxygenated blood to your muscles. Understanding your heart rate, especially during exercise, can help you train more effectively, prevent overexertion, and achieve your fitness goals safely.
Resting Heart Rate
Your resting heart rate (RHR) is the number of times your heart beats per minute when you are completely at rest. It's typically measured first thing in the morning before you get out of bed. A lower RHR generally indicates better cardiovascular fitness. For adults, a normal RHR is usually between 60 and 100 beats per minute (BPM). Athletes often have RHRs below 60 BPM.
Maximum Heart Rate
Your maximum heart rate (MHR) is the highest number of times your heart can realistically beat per minute during strenuous physical activity. A common, though not always perfectly accurate, way to estimate MHR is to subtract your age from 220. For example, a 30-year-old's estimated MHR would be 220 – 30 = 190 BPM.
Heart Rate Training Zones
Heart rate training zones are ranges of your heart rate that correspond to different exercise intensities. Training within specific zones helps you target different physiological benefits:
Zone 1 (Very Light): 50-60% of MHR. This is a recovery zone, good for warming up and cooling down.
Zone 2 (Light): 60-70% of MHR. This zone improves aerobic fitness and endurance.
Zone 3 (Moderate): 70-80% of MHR. This zone improves aerobic fitness and helps build strength and power.
Zone 4 (Hard): 80-90% of MHR. This zone improves anaerobic threshold and speed.
Zone 5 (Maximum): 90-100% of MHR. This zone improves performance and maximal oxygen uptake, but is very intense and should be used sparingly.
How to Use This Calculator
This calculator helps you estimate your heart rate training zones based on your age, resting heart rate, and estimated maximum heart rate. Simply input your age, your typical resting heart rate, and a calculated or measured maximum heart rate. The calculator will then provide you with the BPM ranges for each of the five training zones.
Important Note: Estimated maximum heart rate formulas are generalizations. For a more accurate MHR, consider a stress test performed by a healthcare professional. Always consult with your doctor before starting any new exercise program.
function calculateHeartRate() {
var age = parseFloat(document.getElementById("age").value);
var restingHeartRate = parseFloat(document.getElementById("restingHeartRate").value);
var maxHeartRateInput = parseFloat(document.getElementById("maxHeartRate").value);
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
if (isNaN(age) || isNaN(restingHeartRate) || isNaN(maxHeartRateInput)) {
resultDiv.innerHTML = "Please enter valid numbers for all fields.";
return;
}
if (age <= 0 || restingHeartRate <= 0 || maxHeartRateInput <= 0) {
resultDiv.innerHTML = "Age, Resting Heart Rate, and Maximum Heart Rate must be positive numbers.";
return;
}
if (maxHeartRateInput <= restingHeartRate) {
resultDiv.innerHTML = "Maximum Heart Rate must be greater than Resting Heart Rate.";
return;
}
var maxHeartRate = maxHeartRateInput; // Use the provided max heart rate
var heartRateReserve = maxHeartRate – restingHeartRate;
var zones = {};
zones["zone1_50"] = Math.round(restingHeartRate + (0.50 * heartRateReserve));
zones["zone1_60"] = Math.round(restingHeartRate + (0.60 * heartRateReserve));
zones["zone2_60"] = Math.round(restingHeartRate + (0.60 * heartRateReserve));
zones["zone2_70"] = Math.round(restingHeartRate + (0.70 * heartRateReserve));
zones["zone3_70"] = Math.round(restingHeartRate + (0.70 * heartRateReserve));
zones["zone3_80"] = Math.round(restingHeartRate + (0.80 * heartRateReserve));
zones["zone4_80"] = Math.round(restingHeartRate + (0.80 * heartRateReserve));
zones["zone4_90"] = Math.round(restingHeartRate + (0.90 * heartRateReserve));
zones["zone5_90"] = Math.round(restingHeartRate + (0.90 * heartRateReserve));
zones["zone5_100"] = maxHeartRate; // Maximum heart rate
var htmlOutput = "