Ideal Weight Calculator UK
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 does an ideal-weight calculator show?
A reference weight for your height from standard formulas. It is a rough guideline, not a personal target.
What is the Devine formula?
A classic equation estimating reference weight from height — about 50 kg for a 5-foot male plus roughly 2.3 kg per extra inch, a little less for women.
Is there one ideal weight for a height?
No. A healthy weight is a range that varies with build, muscle and individual factors; a single number cannot capture that.
Why doesn’t the formula account for muscle?
These equations use only height and sex, so they ignore body composition — which is one of their main limitations.
Should I treat the result as a goal?
No. It is general reference information, not a target. Personal guidance is best provided by a healthcare professional.
Who can advise on a healthy weight for me?
A doctor or registered dietitian, who can consider your body, health and circumstances rather than a generic formula.
What an "ideal weight" estimate means
An ideal-weight calculator gives a reference weight for a given height using long-standing formulas. It is best understood as a rough population guideline, not a personal target — a healthy weight is a range that varies with build, muscle, age and individual circumstances.
The formulas behind it
Classic equations such as the Devine formula estimate a reference weight from height (for example, around 50 kg for a 5-foot male plus about 2.3 kg per additional inch, slightly less for women). A BMI-based healthy range (BMI 18.5–24.9 for the height) is another common approach and usually gives a span of several kilograms.
Why a single number is misleading
These formulas were designed for general reference, not individual goals, and they ignore muscle mass and body composition. Two people of the same height can be healthy at different weights, so a single "ideal" figure should never be treated as a goal to chase.
If you have questions about a weight that is healthy for you, a doctor or registered dietitian can give guidance suited to your body and circumstances. This tool offers general information only and is not medical advice.
Results are estimates for general guidance in United Kingdom and may not reflect the latest local rates, fees or rules. Check official sources before making decisions.