BMI Calculator - Mathilde Lacombe


  
  

  
    Free Tool
    BMI Calculator & Healthy Weight Range
    Find your Body Mass Index in seconds — and discover your ideal weight range based on height and age.
  

  
    
      
        Unit System
        
      
      
        Age (years)
        
      
      
        Height (cm)
        
      
      
        Height
        
          
          
        
      
      
        Weight (kg)
        
      
      
        Weight (lbs)
        
      
      
        Gender
        
      
    
    
    
    
      Next step: Calculate your daily water intake or find your calorie needs based on these results.
    
  

  
  
    What is BMI and why does it matter?
    Body Mass Index (BMI) is a simple numerical value calculated from your height and weight. It is used worldwide by doctors, nutritionists and fitness professionals as a quick screening tool to assess whether a person is in a healthy weight range. While BMI does not directly measure body fat, research consistently shows it correlates well with health risks associated with being underweight, overweight or obese.

    BMI categories explained
    
      
        BMI Range Category Health Implication
        
          Below 18.5 Underweight May indicate nutritional deficiency or other health issues
          18.5 – 24.9 Normal weight Associated with the lowest health risks for most people
          25.0 – 29.9 Overweight Moderate risk of heart disease, diabetes and joint problems
          30.0 – 34.9 Obese (Class I) High risk — lifestyle changes strongly recommended
          35.0 and above Obese (Class II+) Very high risk — medical consultation advised
        
      
    

    How is BMI calculated?
    The BMI formula is: BMI = weight (kg) ÷ height² (m²). For example, if you weigh 65 kg and are 1.65 m tall, your BMI = 65 ÷ (1.65 × 1.65) = 23.9, which falls in the normal weight range.

    Limitations of BMI
    BMI is a useful starting point but it has limitations. It does not account for muscle mass — athletes with high muscle may show an "overweight" BMI despite being very healthy. It also does not distinguish between fat stored around the abdomen (more dangerous) versus fat stored elsewhere. Always consult a healthcare professional for a full health assessment.

    Tips to maintain a healthy BMI
    
      Eat a balanced diet rich in vegetables, whole grains, lean protein and healthy fats
      Exercise at least 150 minutes per week at moderate intensity
      Stay hydrated — use our water intake calculator to find your daily target
      Get 7–9 hours of quality sleep — check our sleep calculator for your optimal bedtime
      Track your calorie intake — our calorie calculator gives your personalised daily target

BMI Range	Category	Health Implication
Below 18.5	Underweight	May indicate nutritional deficiency or other health issues
18.5 – 24.9	Normal weight	Associated with the lowest health risks for most people
25.0 – 29.9	Overweight	Moderate risk of heart disease, diabetes and joint problems
30.0 – 34.9	Obese (Class I)	High risk — lifestyle changes strongly recommended
35.0 and above	Obese (Class II+)	Very high risk — medical consultation advised