Normal Heart Rate & Target Zone Calculator
.hr-calculator-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}
.hr-calculator-header {
text-align: center;
margin-bottom: 30px;
}
.hr-calculator-header h2 {
color: #d32f2f;
margin-bottom: 10px;
}
.hr-input-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
margin-bottom: 20px;
}
.hr-input-group {
display: flex;
flex-direction: column;
}
.hr-input-group label {
font-weight: 600;
color: #333;
margin-bottom: 5px;
font-size: 0.9em;
}
.hr-input-group input {
padding: 12px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
}
.hr-input-group input:focus {
border-color: #d32f2f;
outline: none;
}
.hr-calc-btn {
width: 100%;
background-color: #d32f2f;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background 0.2s;
margin-top: 10px;
}
.hr-calc-btn:hover {
background-color: #b71c1c;
}
.hr-results {
margin-top: 30px;
padding: 20px;
background-color: #f9f9f9;
border-radius: 6px;
display: none;
border-left: 5px solid #d32f2f;
}
.hr-result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px solid #eee;
}
.hr-result-row:last-child {
border-bottom: none;
}
.hr-result-label {
font-weight: 600;
color: #555;
}
.hr-result-value {
font-weight: bold;
color: #222;
font-size: 1.1em;
}
.hr-zone-table {
width: 100%;
border-collapse: collapse;
margin-top: 20px;
}
.hr-zone-table th, .hr-zone-table td {
padding: 10px;
text-align: left;
border-bottom: 1px solid #ddd;
}
.hr-zone-table th {
background-color: #eeeeee;
font-size: 0.9em;
}
.hr-article {
max-width: 800px;
margin: 40px auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
}
.hr-article h2 {
color: #2c3e50;
margin-top: 30px;
border-bottom: 2px solid #d32f2f;
padding-bottom: 10px;
display: inline-block;
}
.hr-article p {
margin-bottom: 15px;
}
.hr-article ul {
margin-bottom: 15px;
padding-left: 20px;
}
.hr-article li {
margin-bottom: 8px;
}
@media (max-width: 600px) {
.hr-input-grid {
grid-template-columns: 1fr;
}
}
Calculate Heart Rate Zones
Estimated Maximum Heart Rate (MHR):
— bpm
Heart Rate Reserve (HRR):
— bpm
Your Target Training Zones
Based on the Karvonen Formula
Zone Intensity
Target Range (BPM)
Benefit
function calculateHeartRateZones() {
// 1. Get Input Values
var ageInput = document.getElementById("hrAge");
var restingInput = document.getElementById("hrResting");
var age = parseFloat(ageInput.value);
var restingHR = parseFloat(restingInput.value);
// 2. Validation
if (isNaN(age) || age 120) {
alert("Please enter a valid age between 1 and 120.");
return;
}
if (isNaN(restingHR) || restingHR 220) {
alert("Please enter a valid resting heart rate (typically between 40-100 bpm).");
return;
}
// 3. Calculation Logic
// Standard MHR Formula: 220 – Age
var maxHeartRate = 220 – age;
// Karvonen Formula: TargetHR = ((maxHR – restingHR) * %Intensity) + restingHR
var heartRateReserve = maxHeartRate – restingHR;
// Calculate Zones
// Zone 1: Very Light (50-60%)
var z1Min = Math.round((heartRateReserve * 0.50) + restingHR);
var z1Max = Math.round((heartRateReserve * 0.60) + restingHR);
// Zone 2: Light (60-70%)
var z2Min = Math.round((heartRateReserve * 0.60) + restingHR);
var z2Max = Math.round((heartRateReserve * 0.70) + restingHR);
// Zone 3: Moderate (70-80%)
var z3Min = Math.round((heartRateReserve * 0.70) + restingHR);
var z3Max = Math.round((heartRateReserve * 0.80) + restingHR);
// Zone 4: Hard (80-90%)
var z4Min = Math.round((heartRateReserve * 0.80) + restingHR);
var z4Max = Math.round((heartRateReserve * 0.90) + restingHR);
// Zone 5: Maximum (90-100%)
var z5Min = Math.round((heartRateReserve * 0.90) + restingHR);
var z5Max = maxHeartRate;
// 4. Update UI
document.getElementById("displayMHR").innerText = maxHeartRate + " bpm";
document.getElementById("displayHRR").innerText = heartRateReserve + " bpm";
var tableBody = document.getElementById("zonesTableBody");
tableBody.innerHTML = ""; // Clear previous
var zones = [
{ name: "Zone 1 (50-60%)", range: z1Min + " – " + z1Max + " bpm", benefit: "Warm up, recovery" },
{ name: "Zone 2 (60-70%)", range: z2Min + " – " + z2Max + " bpm", benefit: "Fat burning, endurance" },
{ name: "Zone 3 (70-80%)", range: z3Min + " – " + z3Max + " bpm", benefit: "Aerobic fitness" },
{ name: "Zone 4 (80-90%)", range: z4Min + " – " + z4Max + " bpm", benefit: "Anaerobic capacity" },
{ name: "Zone 5 (90-100%)", range: z5Min + " – " + z5Max + " bpm", benefit: "Max effort, speed" }
];
for (var i = 0; i < zones.length; i++) {
var row = "
" +
"" + zones[i].name + " " + zones[i].range + " " +
"" + zones[i].benefit + " " +
" ";
tableBody.innerHTML += row;
}
// Show results container
document.getElementById("hrResult").style.display = "block";
}
How to Calculate Normal Heart Rate: A Complete Guide
Understanding your heart rate is one of the most effective ways to monitor your health and optimize your fitness workouts. Whether you are an elite athlete or just starting your wellness journey, knowing how to calculate your normal heart rate and target training zones is essential for safety and progress.
What is a Normal Resting Heart Rate?
Your Resting Heart Rate (RHR) is the number of times your heart beats per minute while you are completely at rest. For most adults, a normal resting heart rate ranges between 60 and 100 beats per minute (bpm) .
However, "normal" varies significantly based on fitness levels:
Athletes: Highly conditioned individuals often have resting rates between 40 and 60 bpm. A stronger heart pumps more blood with fewer beats.Average Adult: typically sees rates between 60 and 80 bpm.Factors Affecting RHR: Stress, medication, caffeine, sleep quality, and age can all influence your daily numbers.
The Math Behind the Calculator
To determine your optimal training intensity, this calculator uses the Karvonen Formula . While the basic "220 minus Age" formula gives a rough estimate of your Maximum Heart Rate (MHR), it does not account for your individual fitness level (your resting heart rate). The Karvonen method is considered more accurate for determining target zones.
1. Maximum Heart Rate (MHR)
The standard estimation for the fastest rate your heart can beat under maximum exertion.
Formula: 220 – Age = MHR
Example: For a 40-year-old: 220 – 40 = 180 bpm .
2. Heart Rate Reserve (HRR)
This is the difference between your maximum heart rate and your resting heart rate. It represents the range of heart beats available for exercise.
Formula: MHR – Resting HR = HRR
3. Target Heart Rate
To find the specific beats per minute for a desired intensity (e.g., 70% intensity):
Formula: (HRR × Intensity %) + Resting HR = Target HR
Understanding Heart Rate Zones
Training in specific heart rate zones yields different biological adaptations. Use the calculator above to find your specific numbers.
Zone 1 (50-60%): Very light activity. ideal for warm-ups, cool-downs, and active recovery.Zone 2 (60-70%): Often called the "Fat Burning Zone." Your body relies heavily on fat for fuel. You should be able to hold a conversation easily.Zone 3 (70-80%): The aerobic zone. This improves your cardiovascular system and lung capacity. Breathing becomes heavier.Zone 4 (80-90%): The anaerobic threshold. Your body begins to produce lactic acid faster than it can clear it. Sustainable for shorter periods.Zone 5 (90-100%): Maximum effort. Used for interval training and short bursts of speed.
When to See a Doctor
While calculators provide excellent estimates, they are statistical averages. You should consult a healthcare professional if:
Your resting heart rate is consistently above 100 bpm (tachycardia) or below 50 bpm (bradycardia) without being an athlete.
You experience dizziness, shortness of breath, or chest pain during exercise.
You are taking beta-blockers or other medications that regulate heart rhythm.