function measureBMI () {
// true = metric, false = imperial
let unit = document.getElementById("bmi-metric").checked,
weight = document.getElementById("bmi-weight"),
weightu = document.getElementById("bmi-weight-unit"),
height = document.getElementById("bmi-height"),
heightu = document.getElementById("bmi-height-unit");
if (unit) {
weightu.innerHTML = "KG";
weight.min = 1;
weight.max = 635;
heightu.innerHTML = "CM";
height.min = 54;
height.max = 272;
} else {
weightu.innerHTML = "LBS";
weight.min = 2;
weight.max = 1400;
heightu.innerHTML = "IN";
height.min = 21;
height.max = 107;
}
}
function calcBMI () {
// (A) Get elements
let bmi = null,
unit = document.getElementById("bmi-metric").checked, // true = metric, false = imperial
weight = parseInt(document.getElementById("bmi-weight").value),
height = parseInt(document.getElementById("bmi-height").value),
results = document.getElementById("bmi-results");
// (B) Calculate BMI
// Metric BMI = Mass (kg) / Height (m) square
if (unit) {
height = height / 100;
bmi = weight / (height * height);
}
// Imperial BMI = 703 X Mass (lbs) / Height (in) square
else {
bmi = 703 * (weight / (height * height));
}
// Round off
bmi = Math.round(bmi * 100) / 100; // Round off 2 decimal places
// (C) Show Results
if (bmi < 18.5) {
results.innerHTML = bmi + " - Underweight";
} else if (bmi < 25) {
results.innerHTML = bmi + " - Normal weight";
} else if (bmi < 30) {
results.innerHTML = bmi + " - Pre-obesity";
} else if (bmi < 35) {
results.innerHTML = bmi + " - Obesity class I";
} else if (bmi < 40) {
results.innerHTML = bmi + " - Obesity class II";
} else {
results.innerHTML = bmi + " - Obesity class III";
}
return false;
}
Simple BMI Calculator