Ideal Weight Calculator ZA
Find your ideal body weight (Devine formula) and healthy weight range for your height.
How it works
BMI compares your weight to your height as a general screening number. It is the same formula worldwide; only the units differ.
BMI = weight (kg) ÷ height (m)²- Under 18.5 = underweight
- 18.5–24.9 = healthy
- 25–29.9 = overweight
- 30+ = obese
Frequently asked questions
What is a healthy BMI range?
For most adults, a BMI between 18.5 and 24.9 is considered the healthy range. Below 18.5 is underweight and 25 or above is overweight, though BMI does not account for muscle mass.
Does BMI work the same for everyone?
BMI is a general screening tool, not a diagnosis. It can be misleading for athletes, older adults and during pregnancy, so treat it as one signal among many.
Ideal Weight Calculator
Body Mass Index (BMI) is a quick screening number that compares your weight to your height. This calculator works in the units commonly used in South Africa, so you can enter your height and weight the way you normally measure them and instantly see your BMI and the category it falls into — underweight, healthy weight, overweight or obese.
How to read your result
BMI is a general guide, not a diagnosis. It does not account for muscle mass, body composition, age or ethnicity, so very muscular people may read as "overweight" despite low body fat. Treat it as one signal among many and talk to a healthcare professional in South Africa for personalised advice.
BMI categories
- Below 18.5 — underweight
- 18.5 to 24.9 — healthy weight
- 25 to 29.9 — overweight
- 30 and above — obesity
More questions
Is BMI accurate for athletes?
Not always. Because muscle weighs more than fat, athletes can have a high BMI while being very healthy. Body-fat percentage and waist measurements give a fuller picture.
Does this calculator store my data?
No. Everything is calculated in your browser and nothing is saved or sent anywhere.
Results are estimates for general guidance in South Africa and may not reflect the latest local rates, fees or rules. Check official sources before making decisions.