Calculate your Body Mass Index (BMI) to understand your weight category and set realistic weight loss targets.
Kilograms (kg)
Pounds (lbs)
Centimeters (cm)
Meters (m)
Inches (in)
Feet (ft)
Your BMI Results
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Understanding BMI and Weight Loss
Body Mass Index (BMI) is a widely used metric to categorize a person's weight relative to their height. It provides a general indication of whether an individual is underweight, normal weight, overweight, or obese. While BMI doesn't directly measure body fat, it's a convenient and cost-effective screening tool that correlates well with more direct measures of body fat.
For individuals looking to lose weight, understanding their BMI is a crucial first step. It helps in setting appropriate and healthy weight loss goals. A BMI of 25 or higher generally indicates overweight or obesity, suggesting that weight loss could offer significant health benefits.
Our calculator handles the unit conversions for you, making it easy to get an accurate BMI regardless of how you measure your weight and height.
BMI Categories and Weight Loss Targets
The standard BMI categories are:
Underweight: Below 18.5
Normal weight: 18.5 – 24.9
Overweight: 25.0 – 29.9
Obese: 30.0 and above
For weight loss, the primary goal is typically to move from the 'Overweight' or 'Obese' categories into the 'Normal weight' range. A healthy and sustainable weight loss rate is generally considered to be 1-2 pounds (0.5-1 kg) per week. This is achieved through a combination of a calorie-controlled diet and regular physical activity.
Example:
If an individual weighs 85 kg and is 1.75 meters tall:
BMI = 85 / (1.75 * 1.75) = 85 / 3.0625 = 27.76
This BMI falls into the 'Overweight' category. A weight loss goal might be to reach a weight that results in a BMI between 18.5 and 24.9. For a height of 1.75m, this range corresponds to approximately 57 kg to 76 kg. Therefore, a target weight loss of 9 kg or more would be appropriate to reach a healthy weight range.
Important Considerations
BMI is a screening tool, not a diagnostic one. It doesn't account for muscle mass, bone density, or body composition. Athletes, for example, may have a high BMI due to muscle mass but still be very healthy. It's always recommended to consult with a healthcare professional for personalized advice regarding weight, health, and weight loss strategies.
function calculateBMI() {
var weightInput = document.getElementById("weight");
var weightUnit = document.getElementById("weightUnit").value;
var heightInput = document.getElementById("height");
var heightUnit = document.getElementById("heightUnit").value;
var weight = parseFloat(weightInput.value);
var height = parseFloat(heightInput.value);
var bmiValueElement = document.getElementById("bmiValue");
var bmiCategoryElement = document.getElementById("bmiCategory");
var weightLossAdviceElement = document.getElementById("weightLossAdvice");
var resultTitleElement = document.getElementById("resultTitle");
// Clear previous results
bmiValueElement.textContent = "–";
bmiCategoryElement.textContent = "–";
weightLossAdviceElement.textContent = "";
resultTitleElement.textContent = "Your BMI Results";
// Input validation
if (isNaN(weight) || weight <= 0) {
alert("Please enter a valid weight.");
return;
}
if (isNaN(height) || height <= 0) {
alert("Please enter a valid height.");
return;
}
var weightInKg = weight;
if (weightUnit === "lbs") {
weightInKg = weight * 0.453592;
}
var heightInMeters = height;
if (heightUnit === "cm") {
heightInMeters = height / 100;
} else if (heightUnit === "in") {
heightInMeters = height * 0.0254;
} else if (heightUnit === "ft") {
heightInMeters = height * 0.3048;
}
// Calculate BMI
var bmi = weightInKg / (heightInMeters * heightInMeters);
bmi = bmi.toFixed(2); // Round to 2 decimal places
bmiValueElement.textContent = bmi;
var category = "";
var advice = "";
var targetWeightMin = 0;
var targetWeightMax = 0;
if (bmi = 18.5 && bmi = 25 && bmi = 30
category = "Obese";
advice = "You are in the obese category. Significant health benefits can be achieved through weight loss. Consult a healthcare professional to develop a safe and effective weight loss plan.";
targetWeightMin = 18.5 * (heightInMeters * heightInMeters);
targetWeightMax = 24.9 * (heightInMeters * heightInMeters);
}
bmiCategoryElement.textContent = "Category: " + category;
weightLossAdviceElement.textContent = advice;
// Display target weight range in kg for clarity
var targetWeightMinKg = targetWeightMin.toFixed(1);
var targetWeightMaxKg = targetWeightMax.toFixed(1);
if (category !== "Normal weight") {
weightLossAdviceElement.innerHTML += `Healthy Weight Range for your height: ${targetWeightMinKg} kg – ${targetWeightMaxKg} kg`;
}
}