*Note: This calculator is for educational purposes only and not a substitute for professional medical advice.
How to Calculate Blood Pressure Metrics
While blood pressure is measured directly using a sphygmomanometer, doctors often calculate specific indicators like Mean Arterial Pressure (MAP) and Pulse Pressure to assess cardiovascular health.
1. Mean Arterial Pressure (MAP) Calculation
MAP represents the average pressure in a person's arteries during one cardiac cycle. It is considered a better indicator of perfusion to vital organs than systolic blood pressure alone.
Formula: MAP = [Systolic + (2 × Diastolic)] / 3
Example: If your BP is 120/80 mmHg: MAP = [120 + (2 × 80)] / 3 = 93.33 mmHg.
2. Pulse Pressure Calculation
Pulse pressure is the difference between your systolic and diastolic blood pressure. A high pulse pressure (greater than 60 mmHg) can be a risk factor for cardiovascular disease.
Formula: Pulse Pressure = Systolic – Diastolic
Understanding the Categories
Category
Systolic (mmHg)
Diastolic (mmHg)
Normal
Less than 120
Less than 80
Elevated
120 – 129
Less than 80
Hypertension Stage 1
130 – 139
80 – 89
Hypertension Stage 2
140 or higher
90 or higher
function calculateBP() {
var systolic = parseFloat(document.getElementById('systolic').value);
var diastolic = parseFloat(document.getElementById('diastolic').value);
var resultDiv = document.getElementById('bp-results');
var categoryLabel = document.getElementById('bp-category');
var mapLabel = document.getElementById('map-value');
var ppLabel = document.getElementById('pp-value');
if (isNaN(systolic) || isNaN(diastolic) || systolic <= 0 || diastolic <= 0) {
alert("Please enter valid positive numbers for both Systolic and Diastolic pressure.");
return;
}
if (systolic = 180 || diastolic >= 120) {
category = "Hypertensive Crisis (Seek medical care immediately!)";
color = "#b71c1c";
} else if (systolic >= 140 || diastolic >= 90) {
category = "Hypertension Stage 2";
color = "#d32f2f";
} else if (systolic >= 130 || (diastolic >= 80 && diastolic = 120 && systolic <= 129 && diastolic < 80) {
category = "Elevated Blood Pressure";
color = "#fbc02d";
} else if (systolic < 120 && diastolic < 80) {
category = "Normal Blood Pressure";
color = "#388e3c";
} else {
// Edge case for mixed categories (e.g. 115/85)
category = "Hypertension Stage 1 (based on Diastolic)";
color = "#f57c00";
}
categoryLabel.innerHTML = category;
categoryLabel.style.color = color;
resultDiv.style.display = 'block';
resultDiv.style.borderColor = color;
}