Calculate your maximum heart rate and training zones based on your age.
Enter this for a more accurate result using the Karvonen Formula. Leave blank for standard calculation.
Your Heart Rate Profile
Estimated Max Heart Rate
– BPM
Calculation Method
–
Training Zones (Beats Per Minute)
Zone
Intensity
Target BPM Range
Benefit
Understanding Pulse Rate by Age
Monitoring your pulse rate (heart rate) is one of the most effective ways to gauge the intensity of your exercise and ensure safety. As we age, our cardiovascular system changes, leading to a natural decrease in Maximum Heart Rate (MHR). This calculator helps you define specific target zones tailored to your age and resting physiology.
How is Maximum Heart Rate Calculated?
The most common method for estimating Maximum Heart Rate is the formula: 220 minus your age. For example, a 40-year-old would have an estimated MHR of 180 beats per minute (BPM). While this provides a general baseline, incorporating your Resting Heart Rate (RHR) via the Karvonen Formula offers a more personalized assessment of your fitness level.
The 5 Heart Rate Training Zones
Training in specific heart rate zones yields different physiological adaptations:
Zone 1 (Very Light): 50-60% intensity. Used for warm-ups, cool-downs, and active recovery. Helps improve overall health and recovery.
Zone 2 (Light): 60-70% intensity. Often called the "Fat Burning Zone." It builds basic endurance and trains the body to use fat as fuel.
Zone 3 (Moderate): 70-80% intensity. Improves aerobic capacity and blood circulation. This is the zone for moderate running or swimming.
Zone 4 (Hard): 80-90% intensity. Increases anaerobic tolerance and speed endurance. This is strenuous exercise where breathing becomes heavy.
Zone 5 (Maximum): 90-100% intensity. Used for short interval bursts. Develops maximum performance and speed but can only be sustained for very short periods.
Why Resting Heart Rate Matters
Your Resting Heart Rate (RHR) is the number of times your heart beats per minute while you are at complete rest. A lower RHR generally indicates better cardiovascular fitness and more efficient heart function. By entering your RHR into the calculator above, we use the Heart Rate Reserve (HRR) method, which accounts for the difference between your maximum and resting rates, providing a target range that reflects your actual fitness level rather than just your age.
function calculateHeartRate() {
// 1. Get Inputs
var ageInput = document.getElementById('inputAge');
var rhrInput = document.getElementById('inputRHR');
var resultsArea = document.getElementById('resultsArea');
var dispMaxHR = document.getElementById('dispMaxHR');
var dispMethod = document.getElementById('dispMethod');
var zonesTableBody = document.getElementById('zonesTableBody');
var age = parseFloat(ageInput.value);
var rhr = parseFloat(rhrInput.value);
// 2. Validation
if (isNaN(age) || age 120) {
alert("Please enter a valid age between 1 and 120.");
return;
}
// 3. Calculate Max Heart Rate (Standard Fox Formula)
var maxHR = 220 – age;
// Check if RHR is provided and valid for Karvonen formula
var useKarvonen = !isNaN(rhr) && rhr > 30 && rhr < maxHR;
var methodText = useKarvonen ? "Karvonen (HR Reserve)" : "Standard (220 – Age)";
var heartRateReserve = 0;
if (useKarvonen) {
heartRateReserve = maxHR – rhr;
}
// 4. Define Zones Logic
// Function to calculate BPM at a specific percentage
function getBPM(percentage) {
var decimal = percentage / 100;
if (useKarvonen) {
// Karvonen: (HRR * intensity%) + RHR
return Math.round((heartRateReserve * decimal) + rhr);
} else {
// Standard: MaxHR * intensity%
return Math.round(maxHR * decimal);
}
}
// Zone Definitions
var zones = [
{ id: 1, name: "Very Light", range: "50-60%", minPct: 50, maxPct: 60, desc: "Warm up / Recovery", cssClass: "pr-zone-row-1" },
{ id: 2, name: "Light", range: "60-70%", minPct: 60, maxPct: 70, desc: "Fat Burning / Endurance", cssClass: "pr-zone-row-2" },
{ id: 3, name: "Moderate", range: "70-80%", minPct: 70, maxPct: 80, desc: "Aerobic Fitness", cssClass: "pr-zone-row-3" },
{ id: 4, name: "Hard", range: "80-90%", minPct: 80, maxPct: 90, desc: "Anaerobic Performance", cssClass: "pr-zone-row-4" },
{ id: 5, name: "Maximum", range: "90-100%", minPct: 90, maxPct: 100, desc: "Peak Effort / VO2 Max", cssClass: "pr-zone-row-5" }
];
// 5. Update UI
dispMaxHR.innerHTML = maxHR + " BPM";
dispMethod.innerHTML = methodText;
var tableHTML = "";
for (var i = 0; i < zones.length; i++) {
var z = zones[i];
var minBPM = getBPM(z.minPct);
var maxBPM = getBPM(z.maxPct);
tableHTML += "