10 Seconds (Multiply by 6)
15 Seconds (Multiply by 4)
30 Seconds (Multiply by 2)
60 Seconds (Full Minute)
Sedentary / Average
Active / Athlete
Your Resting Heart Rate
0 BPM
function calculateRHR() {
// 1. Get input values
var beats = document.getElementById('beatCount').value;
var duration = document.getElementById('measurementType').value;
var age = document.getElementById('ageInput').value;
var activity = document.getElementById('fitnessLevel').value;
// 2. Validate inputs
if (!beats || beats <= 0) {
alert("Please enter a valid number of heartbeats.");
return;
}
// 3. Calculate BPM
// Formula: (Beats / Duration in Seconds) * 60
var multiplier = 60 / parseFloat(duration);
var bpm = parseFloat(beats) * multiplier;
// Round to nearest whole number
bpm = Math.round(bpm);
// 4. Generate Assessment Logic
var message = "";
var badgeColor = "#95a5a6"; // default grey
var category = "";
// General adult guidelines (non-athlete)
// Bradycardia: 100
// Athletic adjustment: Athletes often have RHR 40-60
if (activity === 'active') {
if (bpm = 40 && bpm 60 && bpm <= 100) {
category = "Normal";
badgeColor = "#2ecc71"; // lighter green
message = "This is within the normal human range, though slightly elevated for an elite athlete.";
} else {
category = "Elevated";
badgeColor = "#e74c3c"; // red
message = "This is above the normal resting range.";
}
} else {
// Sedentary / Average logic
if (bpm = 60 && bpm = 18 && ageNum 80) {
message += " However, for your age group, a lower RHR usually indicates better cardiovascular fitness.";
} else if (ageNum > 50 && bpm < 70) {
message += " This is a healthy sign for your age group.";
}
}
} else {
category = "Above Average (Tachycardia)";
badgeColor = "#e74c3c";
message = "A resting heart rate above 100 BPM is considered fast (Tachycardia). Stress, caffeine, or fever could be causes.";
}
}
// 5. Update HTML Output
document.getElementById('bpmResult').innerHTML = bpm + ' beats per minute';
var assessmentHTML = 'Category: ' + category + '' + message;
document.getElementById('assessmentText').innerHTML = assessmentHTML;
// Show result box
document.getElementById('resultBox').style.display = 'block';
}
How Is a Resting Heart Rate Calculated?
Your resting heart rate (RHR) is a vital indicator of your overall heart health and cardiovascular fitness. Unlike your active heart rate, which spikes during exercise, your RHR is measured when you are completely relaxed. Understanding how to calculate it accurately allows you to monitor fitness trends and detect potential health issues early.
The Formula for Calculating Heart Rate
The mathematical principle behind calculating heart rate is simple: you are determining the frequency of beats over a standard unit of time, which is one minute (60 seconds). However, you do not need to count for a full minute to get an accurate reading. You can measure for a shorter interval and multiply to estimate the Beats Per Minute (BPM).
The standard formulas used in the calculator above are:
While the 10-second method is the fastest, the 30-second method is generally more accurate because it reduces the margin of error caused by missing a single beat during the count.
How to Measure Your Pulse Manually
To use the calculator effectively, you must first get an accurate count of your pulse. The two most common sites to find your pulse are:
Radial Artery (Wrist): Place your index and middle fingers on the inside of your opposite wrist, just below the thumb base. Press lightly until you feel the pulse.
Carotid Artery (Neck): Place your index and middle fingers on the side of your windpipe, just beneath your jawbone.
Note: Do not use your thumb, as it has its own light pulse which can confuse your count.
What Is a Normal Resting Heart Rate?
For most adults (aged 18+), a normal resting heart rate ranges between 60 and 100 beats per minute (BPM). However, "normal" varies significantly based on factors such as age, fitness level, and medication.
Category
BPM Range
Description
Athlete / Very Active
40 – 60 BPM
Highly efficient heart function.
Average Adult
60 – 100 BPM
Standard range for general health.
Tachycardia
Above 100 BPM
Elevated heart rate (may indicate stress, illness, or poor fitness).
Bradycardia
Below 60 BPM
Slow heart rate (normal for athletes, but may indicate issues in sedentary adults).
Factors That Influence Your Calculation
When calculating your RHR, be aware that external factors can temporarily skew the numbers. For the most accurate calculation, measure your heart rate first thing in the morning before getting out of bed.
Temperature: High humidity or heat can increase RHR by 5–10 beats.
Body Position: Lying down usually produces a lower rate than sitting or standing.
Emotions: Stress, anxiety, or excitement can spike your pulse.
Medication: Beta-blockers tend to lower RHR, while thyroid medications may raise it.
Why Your Calculated RHR Matters
Tracking how your resting heart rate is calculated over time provides insight into your cardiovascular efficiency. Generally, a lower RHR implies more efficient heart function and better cardiovascular fitness. If you notice your calculated RHR consistently rising over several weeks, it may be a sign of overtraining, impending illness, or increased stress levels.