The formula
How it works
Find out whether your weight is in the healthy range for your height, and if not, how much you are above or below it. It uses BMI to set a healthy weight band and shows the gap in real kilograms or pounds.
FAQ
What BMI counts as overweight?
A BMI of 25 to 29.9 is classed as overweight, 30 and above as obese, and 18.5 to 24.9 as a healthy weight. Below 18.5 is underweight. BMI is a useful screen but does not account for muscle, so very muscular people may read high.
How much should I aim to lose?
The calculator shows the weight that would bring you to the top of the healthy range. Losing even 5–10% of body weight brings real health benefits, so treat that gap as a target to work toward gradually rather than all at once.
Is BMI accurate for everyone?
No — it is a population-level screening tool, not a precise individual measure. Athletes with a lot of muscle, older adults who have lost muscle mass, and pregnant women can all get misleading BMI readings, so use it alongside other measures like waist circumference.
What is a healthy rate of weight loss?
Most guidelines suggest aiming for about 0.5–1 kg (1–2 lb) per week through a modest calorie deficit combined with regular activity. Faster loss is harder to sustain and more likely to be regained.
Does waist size matter too?
Yes — waist circumference reflects abdominal fat, which carries extra health risk independent of BMI. A high waist measurement alongside a borderline BMI is a useful extra signal that weight may be worth addressing.
Is the healthy range the same for everyone?
The standard 18.5–24.9 BMI band is a general adult guideline and does not adjust for age, sex, or ethnicity, even though risk thresholds can genuinely differ between groups. It is a reasonable starting point, but a doctor can advise on what is healthy for your specific situation.
Should I see a doctor about my result?
This calculator gives a general estimate, not a medical assessment. If your BMI is well outside the healthy range, or you have concerns about your weight and health, it is worth discussing with a doctor who can consider your full health picture.
About the overweight calculator
This calculator tells you whether your weight is healthy for your height and, if not, how far outside the healthy range you are. It works from body mass index (BMI), which relates weight to height, to define a healthy weight band, then translates any gap into a concrete number of kilograms or pounds. That makes it easy to see not just a category but a real, actionable target.
How to use it
Choose metric or imperial units and enter your height and weight. The calculator returns your BMI, its category, the healthy weight range for your height, and how much you are above or below it. For example, someone 180 cm tall weighing 90 kg has a BMI of about 27.8, in the overweight range, and would need to lose roughly 9 kg to reach the top of the healthy band.
The formula
BMI is weight in kilograms divided by height in metres squared, . The healthy range is a BMI of 18.5 to 24.9, so the healthy weight band for your height runs from to . If your weight is above that band, the excess is the difference from the upper limit; below it, the shortfall is the difference from the lower limit.
Where it is used
Doctors and health services use BMI categories as a first screen for weight-related health risk, and this kind of calculator helps people check where they stand and set a realistic goal. It is a starting point rather than a full diagnosis — waist measurement and body-fat percentage add useful detail — but knowing your healthy weight range is a simple, motivating step toward managing your health.