Enter your weight and height in either metric or imperial units and click Calculate. Your BMI is shown instantly alongside your health category and your healthy weight range for your height.
BMI (Body Mass Index) is a measure of body fat based on height and weight. It is calculated by dividing weight in kilograms by the square of height in metres. A BMI between 18.5 and 24.9 is considered a healthy weight for most adults.
BMI is a useful screening tool but has limitations. It does not directly measure body fat and may overestimate it in muscular people or underestimate it in older adults who have lost muscle mass. It also does not account for where fat is distributed on the body. Always consult a healthcare professional for a full assessment.
- What is a healthy BMI?
- For most adults, a BMI between 18.5 and 24.9 is considered a healthy weight. A BMI below 18.5 is underweight. Between 25 and 29.9 is overweight. 30 or above is obese.
- How do I calculate BMI manually?
- Divide your weight in kilograms by your height in metres squared. For example, if you weigh 75kg and are 1.75m tall: 75 / (1.75 x 1.75) = BMI of 24.5.
- Is BMI different for men and women?
- The standard BMI categories are the same for men and women. However, women naturally have more body fat than men at the same BMI. Some health professionals use different thresholds for different groups.
- What is a healthy BMI for over 60s?
- Some guidelines suggest a BMI of 25 to 27 may be acceptable for older adults, as some additional weight may be protective. Speak to your GP about what is healthy for your specific age and circumstances.
- What are the limitations of BMI?
- BMI is a useful population-level screening tool but has well-known limitations for individuals. It does not distinguish between muscle and fat — a highly muscular person may have a high BMI without being overweight. It also does not account for where fat is distributed on the body, which affects health risk. Age, ethnicity, and sex can also affect the relationship between BMI and body fat percentage. Always consult a healthcare professional for a full assessment.
- Does BMI differ for different ethnic groups?
- Yes. For people of South Asian, Chinese, Japanese, and other Asian backgrounds, health risks associated with excess weight can occur at lower BMI thresholds than for white European populations. The World Health Organization recommends lower action points for these groups — some guidelines suggest overweight from BMI 23 and obesity from BMI 27.5 for Asian populations.
- What is a healthy BMI for over 65s?
- Some guidance suggests that a BMI of 25 to 27 may be acceptable and even protective for older adults, as some additional body weight in later life can be associated with better outcomes in illness. Speak to your GP about what is healthy for your specific age and circumstances — BMI is just one of many factors.