Male
Female
Used for specific calculation variations like the Gulati formula.
Estimated Max Heart Rate
Tanaka Formula (Recommended):— bpm
Standard Formula (220 – Age):— bpm
Gender Specific Formula:— bpm
Heart Rate Training Zones
Based on Tanaka Formula (Best for Active Adults)
Zone
Range (%)
Heart Rate (bpm)
Effect
Understanding Garmin Max Heart Rate Calculations
Setting the correct Maximum Heart Rate (Max HR) on your Garmin device is critical for accurate training metrics. Your Garmin watch uses Max HR to define your training zones, estimate your VO2 Max, calculate Training Load, and determine recovery times. If your Max HR is set too high or too low, your device might report that you are undertraining or overtraining when you aren't.
Why Default Formulas Might Be Wrong
By default, many Garmin devices use the standard formula of 220 minus your age. While simple, this formula has a high margin of error for many individuals, often underestimating Max HR for older athletes and overestimating it for younger ones.
More modern Garmin devices (like the Forerunner 955/965, Fenix 7, and Epix series) often include an "Auto Detection" feature. This feature adjusts your Max HR based on actual performance data recorded during high-intensity activities. However, having a solid mathematical baseline helps you verify if your device's auto-detection is accurate.
The Formulas Used in This Calculator
This calculator provides estimates based on three prominent formulas used in sports science and the Garmin ecosystem:
Tanaka Formula (208 – 0.7 × Age): Widely considered more accurate for healthy adults than the standard formula. It flattens the curve, providing higher estimates for older adults and lower estimates for younger adults.
Standard Formula (220 – Age): The classic method derived by Fox and Haskell. It is simple but can deviate by up to 10-15 beats per minute for many people.
Gulati Formula (206 – 0.88 × Age): Specifically designed for women, as research suggests the standard male-centric formulas often overestimate Max HR for females.
How to Update Max HR on Your Garmin
Once you have your calculated Max HR, you can manually update it in your Garmin Connect settings:
Open the Garmin Connect App on your phone.
Tap the More menu (iOS) or the top-left hamburger menu (Android).
Select Garmin Devices and choose your device.
Select User Settings or User Profile.
Tap Heart Rate & Power Zones > Heart Rate.
Enter your custom Max HR value.
Garmin Heart Rate Zones Explained
Garmin devices typically divide training intensities into 5 zones. Understanding these helps in structured training:
Zone 1 (Warm Up): 50-60% of Max HR. Very light effort, helps with recovery and blood flow.
Zone 2 (Easy): 60-70% of Max HR. The "all day" pace. vital for building endurance and burning fat.
Zone 3 (Aerobic): 70-80% of Max HR. Moderate effort, improves blood circulation and skeletal muscle efficiency.
Zone 4 (Threshold): 80-90% of Max HR. Hard effort, increases lactate threshold and speed endurance.
Zone 5 (Maximum): 90-100% of Max HR. All-out effort, sustainable for only short bursts (sprints).
Should You Trust Auto-Detection?
Garmin's Auto-Detection is generally reliable if you frequently perform high-intensity activities that push you to your limit (like 5K races or interval sprints). If you mostly do steady-state Zone 2 running, the auto-detect feature may calculate a Max HR that is too low. In such cases, using the Tanaka calculation from the tool above serves as a better manual baseline.
function calculateGarminHR() {
// 1. Get Input Values
var ageInput = document.getElementById('garmin_age').value;
var gender = document.getElementById('garmin_gender').value;
// 2. Validate Inputs
if (ageInput === "" || isNaN(ageInput)) {
alert("Please enter a valid age.");
return;
}
var age = parseFloat(ageInput);
if (age 120) {
alert("Please enter a realistic age between 1 and 120.");
return;
}
// 3. Calculate Max HR Formulas
// Standard: 220 – Age
var hrStandard = 220 – age;
// Tanaka: 208 – (0.7 * Age)
var hrTanaka = 208 – (0.7 * age);
// Gender Specific
// Gulati for Female: 206 – (0.88 * Age)
// For Male in this slot, we will use the Gellish formula: 207 – (0.7 * Age) as a modern alternative,
// or just display standard. Let's use Gellish for men as "Modern Linear".
var hrGender;
var genderLabel;
if (gender === 'female') {
hrGender = 206 – (0.88 * age);
genderLabel = "Gulati Formula (Women):";
} else {
// Using Gellish non-linear often cited for men/general: 207 – (0.7 * age)
// Or Inbar: 205.8 – (0.685 * age).
// Let's stick to Hunt or a slight variation for variety, or simply repeat Tanaka if no specific male-only exists.
// Actually, let's use the 'Hunt' formula for active people: 211 – (0.64 * age)
hrGender = 211 – (0.64 * age);
genderLabel = "Hunt Formula (Active Users):";
}
// Round results
hrStandard = Math.round(hrStandard);
hrTanaka = Math.round(hrTanaka);
hrGender = Math.round(hrGender);
// 4. Calculate Zones based on Tanaka (Recommended Baseline)
var baseMax = hrTanaka;
// Zones (Standard Garmin % System)
// Z1: 50-60%, Z2: 60-70%, Z3: 70-80%, Z4: 80-90%, Z5: 90-100%
var z1_min = Math.round(baseMax * 0.50);
var z1_max = Math.round(baseMax * 0.60);
var z2_min = Math.round(baseMax * 0.60); // Garmin usually overlaps, or starts next beat. Let's do range.
var z2_max = Math.round(baseMax * 0.70);
var z3_min = Math.round(baseMax * 0.70);
var z3_max = Math.round(baseMax * 0.80);
var z4_min = Math.round(baseMax * 0.80);
var z4_max = Math.round(baseMax * 0.90);
var z5_min = Math.round(baseMax * 0.90);
var z5_max = baseMax;
// 5. Update UI
document.getElementById('result_standard').innerText = hrStandard + " bpm";
document.getElementById('result_tanaka').innerText = hrTanaka + " bpm";
document.getElementById('result_gender').innerText = hrGender + " bpm";
document.getElementById('label_gender_specific').innerText = genderLabel;
// Populate Table
var tableBody = document.getElementById('zones_table_body');
tableBody.innerHTML = ""; // Clear previous
var zones = [
{ name: "Zone 5 (Max)", range: "90-100%", bpm: z5_min + "-" + z5_max, effect: "Speed & Power", class: "zone-5-color" },
{ name: "Zone 4 (Threshold)", range: "80-90%", bpm: z4_min + "-" + z4_max, effect: "Anaerobic Capacity", class: "zone-4-color" },
{ name: "Zone 3 (Aerobic)", range: "70-80%", bpm: z3_min + "-" + z3_max, effect: "Cardio Endurance", class: "zone-3-color" },
{ name: "Zone 2 (Easy)", range: "60-70%", bpm: z2_min + "-" + z2_max, effect: "Fat Burning / Recovery", class: "zone-2-color" },
{ name: "Zone 1 (Warm up)", range: "50-60%", bpm: z1_min + "-" + z1_max, effect: "Warm up / Cool down", class: "zone-1-color" }
];
for (var i = 0; i < zones.length; i++) {
var row = "