How to use this ideal weight calculator
- Sex, choose male or female, as the Devine formula uses a different starting weight for each.
- Height, pick centimetres or feet and inches, then enter your height.
- Read your ideal weight and healthy weight range, in kg and lb, they update instantly as you type.
Nothing is submitted or stored: the numbers never leave your device, so you can check yours and your family's figures privately.
How ideal weight is calculated
The headline figure uses the Devine formula, a widely cited estimate of ideal body weight. For men it starts at 50 kg and for women at 45.5 kg, then adds 2.3 kg for every inch of height above 5 feet. So a man at 5 ft 10 in is 50 + (10 × 2.3) = 73 kg, while a woman of the same height is 45.5 + (10 × 2.3) = 68.5 kg. Because the formula works in inches, this calculator converts your height first when you enter centimetres.
Alongside that single number, the tool also shows a healthy weight range. This is the weight that gives a Body Mass Index between 18.5 and 24.9, the band the World Health Organization treats as normal for most adults. To work it out we take your height in metres, square it, and multiply by 18.5 for the low end and 24.9 for the high end. A range is often more useful than one figure, because plenty of healthy weights sit inside it.
A general guide, please read
Ideal weight figures are a starting point, not a target to chase. The Devine formula was originally built for medication dosing, not health planning, and neither it nor BMI can tell the difference between muscle and fat or account for your frame size, age, sex and overall fitness. Use these numbers to get a rough sense of where you sit, then talk to a professional about what is right for you.
Medical disclaimer: This calculator is for general information only and is not medical advice. Ideal weight estimates cannot diagnose health or assess individual risk. Always consult a qualified doctor or healthcare professional before making decisions about your weight, diet or health.
Frequently asked questions
How is ideal weight calculated?
This tool uses the Devine formula. Men start at 50 kg and women at 45.5 kg, then add 2.3 kg for every inch above 5 feet. It also shows a healthy range based on a BMI of 18.5 to 24.9 for your height.
What is a healthy weight range?
It is the weight that gives a BMI between 18.5 and 24.9 for your height, which the WHO treats as normal for most adults, shown here in kg and lb.
Is the Devine formula right for me?
It is only a rough reference. The formula was built for drug dosing and ignores muscle mass, frame size and body composition, so treat the result as a guide, not a goal.
Does it work in pounds and feet?
Yes. Switch the height unit to feet and inches, and every result still shows in both kilograms and pounds.
Is my data uploaded?
No, everything is calculated on your device and nothing is sent anywhere.