Desired Heart Rate Calculator
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"name": "What is a desired heart rate?",
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"text": "Desired heart rate, often called target heart rate, is a specific range of heart beats per minute (BPM) you aim to maintain during exercise to achieve specific fitness goals like fat burning or cardiovascular improvement."
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"@type": "Question",
"name": "How is desired heart rate calculated?",
"acceptedAnswer": {
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"text": "It is commonly calculated using the Karvonen Formula: Target Heart Rate = ((Max HR − Resting HR) × %Intensity) + Resting HR. Alternatively, a simpler method uses Max HR × %Intensity."
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}, {
"@type": "Question",
"name": "What is the fat burning zone?",
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"text": "The fat burning zone is typically considered to be 60-70% of your maximum heart rate. In this zone, the body relies more on fat stores for energy compared to glycogen."
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Desired Heart Rate Calculator
Please enter a valid age.
Measure your pulse when you wake up in the morning. Optional (improves accuracy).
Warm Up / Recovery (50-60%)
Fat Burning (60-70%)
Aerobic / Cardio (70-80%)
Anaerobic (80-90%)
VO2 Max (90-100%)
Select your training goal to set the intensity percentage.
Maximum Heart Rate (MHR):0 bpm
Training Intensity:0%
Your Target Heart Rate:0 bpm
Formula used: Standard
Understanding Your Desired Heart Rate
Calculating your desired heart rate is a fundamental step in designing an effective and safe exercise program. Whether your goal is to lose weight, improve cardiovascular health, or train for an athletic event, knowing your target zone ensures you are exerting the right amount of effort—not too little to see results, and not too much to risk injury.
Why Monitor Heart Rate?
Your heart rate is an objective measure of how hard your body is working. By training within specific "zones," you can target different physiological adaptations:
Safety: prevents overexertion.
Efficiency: ensures you aren't wasting time with "junk miles."
Progress Tracking: watching your resting heart rate decrease over time is a sign of improved fitness.
How to Calculate Your Target Heart Rate
This calculator uses two primary methods depending on the data you provide:
1. The Karvonen Formula (Preferred)
If you input your Resting Heart Rate (RHR), the calculator uses the Karvonen formula. This is considered more accurate because it accounts for your individual fitness level.
If you do not know your resting heart rate, the calculator uses the standard method based solely on your Maximum Heart Rate (MHR).
Formula: Target HR = Max HR × % Intensity
Note: Maximum Heart Rate is estimated using the standard equation: 220 - Age.
Heart Rate Training Zones
Zone
Intensity
Benefit
Zone 1: Very Light
50-60%
Warm-up, recovery, and overall health improvement.
Zone 2: Light (Fat Burn)
60-70%
Base endurance and fat mobilization. Best for long durations.
Zone 3: Moderate
70-80%
Improves aerobic capacity and blood circulation.
Zone 4: Hard
80-90%
Increases maximum performance capacity (anaerobic threshold).
Zone 5: Maximum
90-100%
Develops maximum speed and power (short bursts only).
Factors Affecting Your Heart Rate
While the formulas above provide a great baseline, several external factors can influence your heart rate on any given day:
Temperature: Heat and humidity can increase heart rate by 5-10 beats per minute.
Dehydration: As blood volume drops due to sweat, the heart beats faster to circulate oxygen.
Caffeine & Stimulants: Coffee or pre-workout supplements can elevate your baseline heart rate.
Stress & Sleep: Lack of sleep or high emotional stress can raise your resting heart rate.
Always listen to your body. If a calculated heart rate feels dangerously high or uncomfortably easy, adjust your intensity accordingly.
function calculateHeartRate() {
// 1. Get Inputs
var ageInput = document.getElementById("calcAge");
var restingInput = document.getElementById("calcRestingHR");
var intensityInput = document.getElementById("calcIntensity");
var resultBox = document.getElementById("result");
var ageError = document.getElementById("ageError");
// 2. Parse Values
var age = parseFloat(ageInput.value);
var restingHR = parseFloat(restingInput.value);
var intensityPercent = parseFloat(intensityInput.value);
// 3. Validation
if (isNaN(age) || age 120) {
ageError.style.display = "block";
resultBox.style.display = "none";
return;
} else {
ageError.style.display = "none";
}
// 4. Calculate Maximum Heart Rate (Standard Formula)
var maxHR = 220 – age;
var targetHR = 0;
var methodUsed = "";
// 5. Determine Calculation Method
// Check if resting heart rate is a valid number
if (!isNaN(restingHR) && restingHR > 0) {
// Karvonen Formula
// Target Heart Rate = ((max HR − resting HR) × %Intensity) + resting HR
var intensityDecimal = intensityPercent / 100;
var heartRateReserve = maxHR – restingHR;
targetHR = (heartRateReserve * intensityDecimal) + restingHR;
methodUsed = "Karvonen Formula (Age + Resting HR)";
} else {
// Standard Method
// Target Heart Rate = Max HR * %Intensity
targetHR = maxHR * (intensityPercent / 100);
methodUsed = "Standard Method (Max HR × Intensity)";
}
// 6. Update UI
document.getElementById("resMHR").innerHTML = Math.round(maxHR) + " bpm";
// Create range string for intensity (e.g. "60-70%")
// Based on the selected value, we display the range associated in the dropdown text
var selectedText = intensityInput.options[intensityInput.selectedIndex].text;
// Extract the percentage part from text for display, or just show the single target %
document.getElementById("resIntensity").innerHTML = selectedText;
document.getElementById("resTarget").innerHTML = Math.round(targetHR) + " bpm";
document.getElementById("formulaName").innerHTML = methodUsed;
// Show result box
resultBox.style.display = "block";
}