Male
Female
Used to estimate Maximum Heart Rate (MHR).
Enter for Karvonen Formula accuracy. Leave blank for standard formula.
Estimated Maximum Heart Rate (MHR)
0 BPM
Zone
Intensity
Target Range (BPM)
Benefit
Understanding Your Target Heart Rate Zones
Training effectively requires monitoring the intensity of your exercise. Instead of guessing, using a Target Heart Rate Zone Calculator allows you to define specific boundaries based on your age, gender, and resting heart rate. By training in specific "zones," you can tailor your workout to burn fat, build endurance, or increase maximum performance.
How We Calculate Your Zones
This calculator utilizes two primary methods depending on the data you provide:
Standard Method (MHR): This estimates your Maximum Heart Rate (MHR) based on age and gender (typically 220 minus age for men, and 226 minus age for women). Zones are simple percentages of this maximum.
Karvonen Formula (HRR): If you input your Resting Heart Rate (RHR), we use the Heart Rate Reserve method. This is considered more accurate for individuals with varying fitness levels because it accounts for the difference between your resting and maximum heart rate.
The 5 Heart Rate Training Zones
Zone 1 (Very Light, 50-60%): Used for warm-ups and recovery. This zone improves overall health and helps with recovery after hard workouts.
Zone 2 (Light, 60-70%): Often called the "Fat Burning Zone." It builds basic endurance and burns a higher percentage of fat calories.
Zone 3 (Moderate, 70-80%): The aerobic zone. This improves blood circulation and skeletal muscle efficiency. Ideally suited for cardiovascular endurance.
Zone 4 (Hard, 80-90%): The anaerobic threshold. Training here improves your ability to sustain high-speed efforts and handle lactic acid buildup.
Zone 5 (Maximum, 90-100%): Only sustainable for short bursts. This develops maximum performance and speed but carries a higher risk of injury if overused.
Why Gender and Age Matter
Physiologically, heart size and maximum capacity can differ between genders. Generally, women tend to have slightly higher maximum heart rates than men of the same age, which is why gender-specific formulas (like 226 – Age) provide a slightly better baseline estimation than the generic (220 – Age). However, individual fitness levels play the biggest role, which is why including your resting heart rate is highly recommended for precision.
Disclaimer: This tool provides estimates for informational purposes only. It is not medical advice. Always consult a physician before starting a new exercise program, especially if you have existing heart conditions.
function calculateHeartZones() {
// 1. Get Input Values
var ageInput = document.getElementById('calc-age').value;
var gender = document.getElementById('calc-gender').value;
var rhrInput = document.getElementById('calc-rhr').value;
// 2. Validate Age
if (ageInput === "" || isNaN(ageInput) || ageInput 120) {
alert("Please enter a valid age between 1 and 120.");
return;
}
var age = parseFloat(ageInput);
var rhr = rhrInput !== "" ? parseFloat(rhrInput) : null;
// 3. Calculate Maximum Heart Rate (MHR)
// Common formula: Men = 220 – Age, Women = 226 – Age
var mhr;
if (gender === 'female') {
mhr = 226 – age;
} else {
mhr = 220 – age;
}
// 4. Determine Calculation Method (Standard vs Karvonen)
var useKarvonen = (rhr !== null && !isNaN(rhr) && rhr > 30 && rhr < mhr);
var calculationMethodText = useKarvonen ?
"Calculated using the Karvonen Formula (Heart Rate Reserve)." :
"Calculated using Standard Age-Predicted Maximum.";
// 5. Define Zone Percentages
var zones = [
{ id: 1, minPct: 0.50, maxPct: 0.60, name: "Zone 1", desc: "Very Light (Warm up)", benefit: "Recovery / Health" },
{ id: 2, minPct: 0.60, maxPct: 0.70, name: "Zone 2", desc: "Light (Fat Burn)", benefit: "Endurance / Fat Loss" },
{ id: 3, minPct: 0.70, maxPct: 0.80, name: "Zone 3", desc: "Moderate (Aerobic)", benefit: "Cardio Fitness" },
{ id: 4, minPct: 0.80, maxPct: 0.90, name: "Zone 4", desc: "Hard (Anaerobic)", benefit: "Speed / Strength" },
{ id: 5, minPct: 0.90, maxPct: 1.00, name: "Zone 5", desc: "Maximum (VO2 Max)", benefit: "Peak Performance" }
];
// 6. Calculate Ranges and Build HTML
var tableBody = "";
for (var i = 0; i < zones.length; i++) {
var zone = zones[i];
var minBpm, maxBpm;
if (useKarvonen) {
// Karvonen: TargetHR = ((MHR – RHR) * %Intensity) + RHR
var hrr = mhr – rhr;
minBpm = Math.round((hrr * zone.minPct) + rhr);
maxBpm = Math.round((hrr * zone.maxPct) + rhr);
} else {
// Standard: TargetHR = MHR * %Intensity
minBpm = Math.round(mhr * zone.minPct);
maxBpm = Math.round(mhr * zone.maxPct);
}
tableBody += "