BMI Calculator

'; } else { result += '

Gender: Female

'; } result += '

Date of Birth: ' + dob + '

'; if (bmi < 18.5) { result += '

You are underweight.

'; } else if (bmi >= 18.5 && bmi < 24.9) { result += '

You have a normal weight.

'; } else if (bmi >= 25 && bmi < 29.9) { result += '

You are overweight.

'; } else { result += '

You are obese.

'; }// Color-coded BMI categories const progressBar = document.getElementById('progressBar'); let progressBarColor = '';if (bmi < 16) { progressBarColor = 'bg-danger'; } else if (bmi >= 16 && bmi < 18.5) { progressBarColor = 'bg-warning'; } else if (bmi >= 18.5 && bmi < 25) { progressBarColor = 'bg-success'; } else if (bmi >= 25 && bmi < 30) { progressBarColor = 'bg-warning'; } else { progressBarColor = 'bg-danger'; }progressBar.className = 'progress-bar ' + progressBarColor; progressBar.style.width = (bmi < 0 ? 0 : bmi) + '%';// Calculation details details = `

Calculation Details:

Weight: ${weight} kg

Height: ${height * 100} cm

BMI Formula: BMI = Weight (kg) / (Height (m) * Height (m))

BMI Calculation: BMI = ${weight} / (${height} * ${height}) = ${bmi}

Age: ${age} years

`;// Store the calculation in history history.push({ date: new Date(), bmi: bmi, details: details }); displayHistory(); } else { result = '

Invalid input. Please enter valid values.

'; }document.getElementById('result').innerHTML = result; document.getElementById('calculationDetails').innerHTML = details; }function calculateAge(birthDate) { const currentDate = new Date(); const yearsDifference = currentDate.getFullYear() - birthDate.getFullYear();if ( currentDate.getMonth() < birthDate.getMonth() || (currentDate.getMonth() === birthDate.getMonth() && currentDate.getDate() < birthDate.getDate()) ) { return yearsDifference - 1; }return yearsDifference; }function displayHistory() { const historyList = document.getElementById('historyList'); historyList.innerHTML = ''; history.forEach((item, index) => { const li = document.createElement('li'); li.innerHTML = `Calculation ${index + 1}:
${item.date.toLocaleString()}
${item.details}`; historyList.appendChild(li); }); }

Concepts

Body mass index (BMI) is a measure of body fat based on height and weight that is used to screen for weight categories that may lead to health problems. BMI is calculated by dividing a person’s weight in kilograms (kg) by the square of their height in meters (m).

Formula

The following formula is used to calculate BMI:

BMI = weight (kg) / height^2 (m^2)

Interpretation

A BMI of 18.5 to 24.9 is considered to be a healthy weight. A BMI of 25.0 to 29.9 is considered overweight. A BMI of 30.0 or higher is considered obese.

Benefits

BMI is a simple and inexpensive way to screen for weight categories that may lead to health problems. It can be used by people of all ages and genders.

Interesting facts

• BMI was developed in the late 1800s by a Belgian statistician named Adolphe Quetelet.
• BMI is used in over 100 countries around the world.
• BMI is not a perfect measure of body fatness. It does not take into account muscle mass or body composition.
• BMI is most accurate for adults between the ages of 20 and 65.

Scholarly references

• Clinical Assessment of Nutritional Status by Robert J. Fanelli (2012)
• Obesity and the Body Mass Index: Or Why We Are Still Measuring Abdominal Obesity by Kelly Brownell and Joann E. Manson (2005)
• Body Mass Index and Mortality by Katherine M. Flegal, MD, MPH, and Barry M. Popkin, PhD (2001)

Examples

The following table shows some examples of BMI calculations:

Weight (kg)	Height (m)	BMI
60	1.6	23.4
70	1.7	24.2
80	1.8	25.0

Applications

BMI can be used by individuals, healthcare professionals, and public health officials.

• Individuals: Individuals can use BMI to track their weight over time and to assess their risk of developing weight-related health problems.
• Healthcare professionals: Healthcare professionals can use BMI to screen for weight categories that may lead to health problems and to develop treatment plans for obese patients.
• Public health officials: Public health officials can use BMI to track the prevalence of obesity in a population and to develop public health interventions to promote healthy weight.

Conclusion

BMI is a simple and inexpensive tool that can be used to screen for weight categories that may lead to health problems. It is important to note that BMI is not a perfect measure of body fatness and that other factors, such as muscle mass and body composition, should also be considered when assessing a person’s health.