BMI Calculator

Calculate your Body Mass Index (BMI) to understand your weight status and get personalized health recommendations.

Examples

• 70 kg, 175 cm = BMI 22.9 (Normal weight)
• 150 lbs, 5'6" = BMI 24.2 (Normal weight)
• 80 kg, 160 cm = BMI 31.2 (Obese)

How to Use the BMI Calculator

Using our BMI calculator is simple and straightforward. Follow these steps to get your BMI calculation:

  1. Choose your preferred unit system (Metric or Imperial)
  2. Enter your weight in kilograms (kg) or pounds (lbs)
  3. Enter your height in centimeters (cm) or feet and inches
  4. Click "Calculate BMI" to get your results

The calculator will provide your BMI value, weight category, healthy weight range, and personalized recommendations based on your results.

Understanding BMI (Body Mass Index)

Body Mass Index (BMI) is a widely used metric for assessing whether a person has a healthy weight for their height. It's calculated by dividing a person's weight by the square of their height and is expressed in units of kg/m² for metric or lbs/in² × 703 for imperial.

BMI is used by healthcare professionals worldwide as a screening tool to identify potential weight-related health risks. While BMI is a useful indicator, it's important to remember that it doesn't distinguish between muscle mass and fat mass, so it may not be entirely accurate for athletes or individuals with high muscle mass.

BMI Categories

  • Underweight: BMI less than 18.5
  • Normal weight: BMI 18.5 to 24.9
  • Overweight: BMI 25 to 29.9
  • Obese: BMI 30 or greater

Formula & Calculation Method

The BMI formula varies depending on the unit system used:

Metric Formula

BMI = weight (kg) / height (m)²

Imperial Formula

BMI = (weight (lbs) / height (inches)²) × 703

The multiplication by 703 in the imperial formula is a conversion factor to ensure consistency with the metric calculation.

Frequently Asked Questions

Is BMI accurate for everyone?

BMI is a useful screening tool but has limitations. It doesn't distinguish between muscle and fat mass, so athletes or muscular individuals might have a high BMI despite being healthy. It's best used as one indicator among others for assessing health.

What's a healthy BMI range?

A healthy BMI range for adults is typically between 18.5 and 24.9. However, this can vary based on age, gender, ethnicity, and other factors. Consult with a healthcare provider for personalized advice.

How often should I check my BMI?

For most people, checking BMI monthly or quarterly is sufficient. If you're actively trying to lose or gain weight, you might want to check it more frequently as part of tracking your progress.

Should children use this BMI calculator?

This calculator is designed for adults. Children and teenagers need age and sex-specific BMI percentiles rather than the standard adult BMI categories. Consult a pediatrician for children's BMI assessment.

Tips & Best Practices

  • Weigh yourself at the same time of day for consistency
  • Use BMI as one tool among many for assessing health
  • Consider consulting healthcare professionals for personalized advice
  • Focus on overall health and fitness, not just BMI numbers
  • Remember that BMI doesn't account for muscle mass or body composition
  • Track trends over time rather than focusing on single measurements
  • Combine BMI with other health indicators like waist circumference
  • Don't rely solely on BMI if you're an athlete or have a muscular build