Calculate your estimated Maximum Heart Rate (MHR) using MyZone's specific formula and see your personalized effort zones.
If you have hit a higher HR on a MyZone belt than the formula predicts, enter it here. MyZone automatically adjusts to your historical peak.
Your Calculated Max Heart Rate
0 BPM
Your MyZone Effort Zones (MEPs)
Zone Color
Intensity (%)
Heart Rate Range (BPM)
MEPs per Min
How Does MyZone Calculate Max Heart Rate?
Understanding your Maximum Heart Rate (MHR) is critical for effective heart rate training. Unlike generic fitness trackers that often use the outdated "220 minus age" formula, MyZone utilizes a more accurate scientific equation to establish your baseline.
The Hunt Formula
By default, MyZone calculates your MHR using the Hunt Formula. This formula is derived from a study published in the Journal of the American College of Cardiology and is considered more accurate for a wider range of the population than the standard Fox method.
The calculation is:
211 - (0.64 × Age) = Estimated MHR
For example, a 30-year-old individual would have a predicted max heart rate of approximately 192 BPM, whereas the old formula would have predicted 190 BPM.
Automatic Biometric Calibration
One of MyZone's distinct features is its ability to auto-calibrate. The formula above is just a starting point. If you wear your MyZone belt during a high-intensity workout and sustain a heart rate higher than your estimated maximum for a set duration, the MyZone system effectively "learns" your true physiological limit.
When this happens, your MHR setting in the app is automatically updated to this new observed peak. This ensures your zones (Grey, Blue, Green, Yellow, Red) remain accurate relative to your actual fitness level, rather than a theoretical average.
Understanding MyZone Effort Points (MEPs)
Your MyZone status is determined by which zone you are training in, relative to your Max Heart Rate. The system rewards effort rather than just fitness, leveling the playing field for users of different ages and abilities.
Grey Zone (50-59%): 1 MEP/min. Warm-up and recovery.
Blue Zone (60-69%): 2 MEPs/min. Light endurance and fat burning.
Green Zone (70-79%): 3 MEPs/min. Aerobic conditioning and steady state.
Yellow Zone (80-89%): 4 MEPs/min. Anaerobic threshold training.
Red Zone (90-100%): 4 MEPs/min. Peak exertion and VO2 max training.
Use the calculator above to determine your zones based on either the standard MyZone formula or your own known peak heart rate.
function calculateMyZone() {
// 1. Get Inputs
var ageInput = document.getElementById('mz_age').value;
var peakInput = document.getElementById('mz_observed_peak').value;
var resultDiv = document.getElementById('mz-result');
var mhrDisplay = document.getElementById('mhr_value');
var methodText = document.getElementById('method_explanation');
var zonesBody = document.getElementById('zones_body');
// 2. Validate Age
if (!ageInput || ageInput formulaMHR) {
finalMHR = Math.round(observedPeak);
methodUsed = "Based on your observed peak heart rate, which exceeds the standard formula estimate.";
} else if (!isNaN(observedPeak) && observedPeak 0) {
// Even if they enter a lower peak, MyZone usually defaults to the formula until the user PROVES they can go higher,
// but for a calculator, if they insist their peak is lower (rare), we stick to formula as baseline
// or we could allow manual override. MyZone logic usually prevents lowering MHR easily without support,
// but auto-updates upwards. We will stick to the Higher of the two logic typical of their system.
methodUsed = "Your observed peak is lower than the formula estimate. MyZone typically uses the formula baseline until a higher peak is detected.";
}
// 5. Update MHR Display
mhrDisplay.innerHTML = finalMHR;
methodText.innerHTML = methodUsed;
// 6. Calculate Zones
// MyZone Zones:
// Grey: 50-59%
// Blue: 60-69%
// Green: 70-79%
// Yellow: 80-89%
// Red: 90-100%
var zones = [
{
name: "Red Zone",
class: "zone-red",
range: "90% – 100%",
min: Math.round(finalMHR * 0.90),
max: Math.round(finalMHR * 1.0),
meps: "4"
},
{
name: "Yellow Zone",
class: "zone-yellow",
range: "80% – 89%",
min: Math.round(finalMHR * 0.80),
max: Math.round(finalMHR * 0.89),
meps: "4"
},
{
name: "Green Zone",
class: "zone-green",
range: "70% – 79%",
min: Math.round(finalMHR * 0.70),
max: Math.round(finalMHR * 0.79),
meps: "3"
},
{
name: "Blue Zone",
class: "zone-blue",
range: "60% – 69%",
min: Math.round(finalMHR * 0.60),
max: Math.round(finalMHR * 0.69),
meps: "2"
},
{
name: "Grey Zone",
class: "zone-gray",
range: "50% – 59%",
min: Math.round(finalMHR * 0.50),
max: Math.round(finalMHR * 0.59),
meps: "1"
}
];
// 7. Render Table
var tableHTML = "";
// Loop through zones
for (var i = 0; i < zones.length; i++) {
var z = zones[i];
tableHTML += "